CN108873135A - A kind of near-infrared narrow band filter and infrared imaging system - Google Patents

Abstract

The present invention relates to a kind of near-infrared narrow band filter and infrared imaging system, wherein near-infrared narrow band filter includes：The IR membrane system of the substrate side is arranged in substrate；The IR membrane system includes the first high refractive index layer and the first low-index film being alternately coated with, and the outermost layer of the IR membrane system is the first low-index film；In the wave-length coverage of 800~1200nm, the IR membrane system has a passband wave band, two transition wave bands and two cut-off wave bands, the passband wave band is located between two described two cut-off wave bands, and the little bellow section is between the passband wave band and the cut-off wave band；The passband wave band has central wavelength, and in the range of incidence angle changes from 0 ° to 30 °, the central wavelength drift band of the passband wave band is between 7nm~13nm.Under the premise of guaranteeing high transmittance, narrow band filter passband center wavelengths are reduced with angle drift amount, improve image quality.

Description

A near-infrared narrow-band filter and an infrared imaging system

technical field

The invention relates to an optical filter and an infrared imaging system, in particular to a near-infrared narrow-band optical filter and an infrared imaging system.

Background technique

With the development of science and technology, face devices, gesture recognition, etc. Function.

Near-infrared narrow-band filters are required for face recognition and gesture recognition, which can enhance the near-infrared light in the copper strip and cut off the visible light in the environment. Usually near-infrared narrow-band filters include two film systems, namely IR band-pass film system and long-wave pass AR film system. However, the optical filter in the prior art has poor anti-reflection effect on near-infrared light and visible light cut-off effect, and there is a problem that the thickness of the film system is relatively thick, which leads to the assembly of the optical filter in face recognition, gesture recognition, etc. After recognition and other devices, the imaging effect is poor and the recognition accuracy is not high.

Contents of the invention

The object of the present invention is to provide a near-infrared narrow-band filter and an infrared imaging system to solve the problem of poor imaging effect of the near-infrared filter.

In order to achieve the purpose of the above invention, the present invention provides a near-infrared narrow-band filter, including: a substrate, an IR film system arranged on one side of the substrate;

The IR film system includes alternately plated first high-refractive index film layers and first low-refractive-index film layers, and the outermost layers of the IR film system are all first low-refractive index film layers; In the wavelength range, the IR film system has a pass band, two transition bands and two cut-off bands, the pass band is located between the two cut-off bands, and the transition band is located between the pass bands. between the band band and the cut-off band;

The passband band has a central wavelength, and within the range where the incident angle changes from 0° to 30°, the central wavelength shift range of the passband band is between 7nm and 13nm.

According to one aspect of the present invention, within the range where the incident angle changes from 20° to 30°, for every 1° change in the incident angle, the shift amplitude of the central wavelength of the passband band is less than 5 nm.

According to an aspect of the present invention, the bandwidth of the passband band is less than 400nm.

According to one aspect of the present invention, within the wavelength range of 800-1200 nm, the transmittance in the passband band is greater than 90%, and the transmittance in the cutoff band is less than 0.1%.

According to one aspect of the present invention, the steepness of the curves at the UV side and the IR side of the passband band is between 7nm and 13nm.

According to one aspect of the present invention, the first high refractive index film layer is a hydrogenated silicon layer;

In the wavelength range of 800-1200 nm, the refractive index of the first high-refractive index film layer is greater than 3.5, and the extinction coefficient is less than 0.002.

According to one aspect of the present invention, at a wavelength of 850nm, the refractive index of the first high refractive index film layer is greater than 3.6;

At the wavelength of 940nm, the refractive index of the first high refractive index film layer is greater than 3.55.

According to one aspect of the present invention, the first high refractive index film layer is a sputtering reaction film layer, and in the presence of hydrogen, the sputtering reaction temperature is 80°C-300°C, and the sputtering rate is 0.1nm/s ≤v≤1nm/s.

According to one aspect of the present invention, the hydrogen gas is introduced at an adjustable flow rate, and the flow rate satisfies 10sccm≤v1≤50sccm.

According to one aspect of the present invention, the physical thickness relationship between the first high refractive index film layer and the first low refractive index film layer satisfies: 0.01≤D _L /D _H ≤100, where D _L and D _H are respectively Indicates the physical thickness of the first low-refractive-index film layer and the first high-refractive-index film layer.

According to one aspect of the present invention, within the range where the incident angle changes from 0° to 10°, the central wavelength shift amplitude of the passband band is between 0.5nm and 1.5nm, and for every 1° change in the incident angle, the The central wavelength drift of the passband band is less than 1.5nm;

In the range where the incident angle changes from 0° to 20°, the central wavelength shift range of the passband band is between 2.5nm and 8nm, and in the range where the incident angle changes from 10° to 20°, every 1° change in the incident angle , the central wavelength shift amplitude of the passband band is less than 6nm;

In the range where the incident angle changes from 0° to 40°, the central wavelength shift amplitude of the passband band is between 12nm and 20nm, and in the range where the incident angle changes from 0° to 10°, every time the incident angle changes by 1°, The central wavelength shift amplitude of the passband band is less than 8nm.

According to an aspect of the present invention, it also includes an AR film system;

The IR film system and the AR film system are oppositely located on both sides of the substrate;

The AR film system includes alternately plated second high-refractive-index film layers and second low-refractive-index film layers, and the outermost layers of the AR film system are both second low-refractive index film layers.

According to one aspect of the present invention, in the wavelength range of 350-1200nm, the AR film system has a passband region, and its transmittance is greater than 90%, and a cutoff region, and its transmittance is less than 0.1%;

In the wavelength range of 800-1200nm, the AR film system also has a transition region, and its transmittance is between 0.1%-90%.

According to one aspect of the present invention, the total thickness of the film layers of the IR film system and the AR film system is less than 9.8 μm.

According to one aspect of the present invention, the full width at half maximum of the near-infrared narrow-band filter is less than 120nm.

According to one aspect of the present invention, the refractive index of the first low refractive index film layer is less than 3, and its material is SiO ₂ , Nb ₂ O ₅ , Ta ₂ O ₅ , TiO ₂ , Al ₂ O ₃ , ZrO ₂ , A combination of one or more of Pr ₆ O ₁₁ , La ₂ O ₃ , Si ₂ N, SiN, Si ₂ N ₃ , Si ₃ N ₄ ;

The refractive index of the second low refractive index film layer is less than 3, and its material is SiO ₂ , Nb ₂ O ₅ , Ta ₂ O ₅ , TiO ₂ , Al ₂ O ₃ , ZrO ₂ , Pr ₆ O ₁₁ , La ₂ A combination of one or more of O ₃ , Si ₂ N, SiN, Si ₂ N ₃ , and Si ₃ N ₄ .

In order to achieve the purpose of the above invention, the present invention provides an infrared imaging system, which is characterized in that it includes an IR emitting system and an IR receiving system;

The IR emitting system includes an IR emitting light source and a first lens assembly for projecting light emitted by the IR emitting light source;

The IR receiving system includes a near-infrared narrow-band filter, a second lens assembly and an infrared image sensor;

The infrared narrowband filter is located between the second lens assembly and the infrared image sensor.

According to one aspect of the present invention, the first lens component includes an infrared light source collimating lens and a diffraction component disposed on the infrared light source collimating lens.

According to a solution of the present invention, under the premise of ensuring the high transmittance of the near-infrared filter of the present invention, the drift of the passband center wavelength of the narrow-band filter with angle can be greatly reduced, and the transition of the narrow-band filter is improved. The steepness of the area improves the imaging quality, further improves the signal-to-noise ratio in face recognition and gesture recognition systems, reduces the total thickness of the film layer and the total time of coating, reduces the production cost, and saves the use cost for end customers.

According to a solution of the present invention, by setting the outer sides of the IR film system and the AR film system respectively as the first low refractive index film layer and the second low refractive index film layer, it is beneficial for the IR film system and the AR film system to adhere to the substrate. On, and its hardness is high, wear resistance is good, and corrosion resistance is strong, thereby helps to guarantee the structural stability of IR film system and AR film system of the present invention, and improves the service life of IR film system and AR film system, further improves The service life of the infrared narrowband filter of the present invention is improved. At the same time, the thickness of the near-infrared narrow-band filter of the present invention is small, which saves the production cost of the present invention.

According to a solution of the present invention, through the setting of the above conditions, the plated first high-refractive index film layer has good film properties, so that the first high-refractive index film layer reaches a relatively high refractive index, further enabling the present invention The imaging effect of the near-infrared narrow-band filter is better.

Description of drawings

Fig. 1 schematically represents the structural diagram of the near-infrared filter according to an embodiment of the present invention;

Fig. 2 schematically represents the wavelength and transmission curve relation diagram of the IR film system of the near-infrared optical filter according to an embodiment of the present invention;

Fig. 3 schematically represents the structure diagram of the near-infrared filter according to another embodiment of the present invention;

Fig. 4 schematically shows a structure diagram of an infrared imaging system according to an embodiment of the present invention.

Fig. 5 schematically represents the graph of the relationship between the transmittance of the IR film layer and the wavelength according to Embodiment 1 of the present invention;

Fig. 6 schematically represents the graph of the relationship between the transmittance of the IR film layer and the wavelength according to Embodiment 2 of the present invention;

Fig. 7 schematically represents the graph of the relationship between the transmittance of the IR film layer and the wavelength according to Embodiment 3 of the present invention;

Fig. 8 schematically represents the graph of the relationship between the transmittance of the IR film layer and the wavelength according to Embodiment 4 of the present invention;

Fig. 9 schematically shows the graph of the relationship between the transmittance of the AR film layer and the wavelength according to Embodiment 4 of the present invention;

Fig. 10 schematically represents the graph of the relationship between the transmittance of the IR film layer and the wavelength according to Embodiment 5 of the present invention;

FIG. 11 schematically shows the relationship between the transmittance of the AR film layer and the wavelength according to Embodiment 5 of the present invention.

Detailed ways

In order to more clearly describe the embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings that are used in the embodiments. Apparently, the drawings in the following description are only some embodiments of the present invention, and those skilled in the art can also obtain other drawings according to these drawings without creative efforts.

When describing the embodiments of the present invention, the terms "vertical", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", " The orientation or positional relationship expressed by "horizontal", "top", "bottom", "inner" and "outer" is based on the orientation or positional relationship shown in the relevant drawings, which are only for the convenience of describing the present invention and simplifying the description, and It is not to indicate or imply that the device or element referred to must have a particular orientation, be constructed, or operate in a particular orientation, and thus the above terms should not be construed as limiting the invention.

The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments, and the embodiments cannot be repeated here one by one, but the embodiments of the present invention are not therefore limited to the following embodiments.

As shown in FIG. 1 , according to an embodiment of the present invention, a near-infrared narrow-band filter of the present invention includes a substrate 11 and an IR film system 12 . In this embodiment, the IR film system 12 is disposed on one side of the substrate 11 . The IR film system 12 is a multi-layer film structure. In this embodiment, the IR film system 12 includes first high-refractive-index film layers 121 and first low-refractive-index film layers 122 that are plated alternately. In this embodiment, the refractive index of the first high refractive index film layer 121 is greater than 3, and the refractive index of the first low refractive index film layer 122 is less than 3. In the IR film system 12 , the outermost layer of the IR film system 12 (ie the position where the IR film system 12 is in contact with the substrate 11 and the incident medium) is the first low refractive index film layer 122 . In this embodiment, the total thickness of the IR film system 12 of the near-infrared narrow-band filter is less than 9.8 μm. In this embodiment, the full width at half maximum of the near-infrared narrow-band filter is less than 120 nm. Further, the total thickness of the IR film system 12 of the near-infrared narrow-band filter is less than 8 μm. In this embodiment, the full width at half maximum of the near-infrared narrow-band filter is less than 114 nm. By setting the outside of the IR film system 12 as the first low refractive index film layer 122, it is beneficial for the IR film system 12 to be attached to the substrate 11, and it has high hardness, good wear resistance, and strong corrosion resistance, which is beneficial to ensure this The structure of the inventive IR film system 12 is stable, and the service life of the IR film system 12 is improved, further improving the service life of the infrared narrowband filter of the present invention. At the same time, the thickness of the near-infrared narrow-band filter of the present invention is small, which saves the production cost of the present invention.

According to an embodiment of the present invention, the refractive index of the first low refractive index film layer 122 is less than 3. In this embodiment, the material of the first low refractive index film layer 122 is SiO ₂ , Nb ₂ O ₅ , Ta ₂ O ₅ , TiO ₂ , Al ₂ O ₃ , ZrO ₂ , Pr ₆ O ₁₁ , La ₂ O ₃ , Si ₂ N, SiN, Si ₂ N ₃ , Si ₃ N ₄ or a combination of one or more.

According to one embodiment of the present invention, in the wavelength range of 800-1200nm, since the IR film system 12 alternately coats the first high-refractive-index film layer 121 and the first low-refractive-index film layer 122, the Interference effects thus produce passband, transition and cutoff bands. In this embodiment, in the wavelength range of 800-1200nm, the IR film system 12 has a passband band, two transition bands and two cutoff bands, and the passband band is located between the two cutoff bands, that is, two The cut-off band is located on both sides of the pass-band band, and the transition band is located between the pass-band band and the cut-off band. In this embodiment, the passband band has a central wavelength, and within the range where the incident angle changes from 0° to 30°, the central wavelength shift range of the passband band is between 7nm and 13nm, that is, the center of the passband band The amplitude of wavelength shift is greater than 7nm and less than 13nm. At the same time, within the range where the incident angle changes from 20° to 30°, the central wavelength shift of the passband band is less than 5nm when the incident angle changes by 1°.

According to one embodiment of the present invention, the physical relationship between the first high-refractive index film layer 121 and the first low-refractive index film layer 122 satisfies: 0.01≤D _L /D _H ≤100, where _DL and D _H represent The physical thickness of the first low refractive index film layer and the first high refractive index film layer. By setting the physical thicknesses of the first high-refractive index film layer 121 and the first low-refractive index film layer 122 within the above-mentioned range, it is beneficial to reduce the drift amplitude of the central wavelength of the passband band of the IR film system 12, which improves the present invention. image quality. In this embodiment of the present invention, the first low refractive index film layer 122 is a silicon nitride layer. The first low refractive index film layer 122 is made of silicon nitride material, which has excellent adhesion, high hardness, good wear resistance, and strong corrosion resistance, thus ensuring the connection strength and structural strength of the IR film system 12 and the substrate 11, and The service life of the IR film system 12 is improved.

It should be pointed out that the IR film is an infrared cut film.

Further, in this embodiment, within the wavelength range of 800-1200nm, the IR film system 12 has a pass band, two transition bands and two cut-off bands, the pass band is located between the two cut-off bands, That is, the two cut-off bands are located on both sides of the pass-band band, and the transition band is located between the pass-band band and the cut-off band. In this embodiment, the passband band has a central wavelength, and within the range where the incident angle changes from 0° to 30°, the central wavelength drift range of the passband band is between 8nm and 12nm, that is, the center of the passband band The amplitude of wavelength shift is greater than 8nm and less than 12nm. At the same time, within the range where the incident angle changes from 20° to 30°, the central wavelength shift of the passband band is less than 5nm when the incident angle changes by 1°.

In this embodiment, within the range where the incident angle changes from 0° to 10°, the central wavelength shift range of the passband band is between 0.5nm and 1.5nm, and every time the incident angle changes by 1°, the center wavelength of the passband band The amplitude of wavelength shift is less than 1.5nm.

In this embodiment, within the range where the incident angle changes from 0° to 20°, the central wavelength shift amplitude of the passband band is between 2.5nm and 8nm, and within the range where the incident angle changes from 10° to 20°, the incident angle For every 1° change, the central wavelength shift of the passband band is less than 6nm.

In this embodiment, when the incident angle changes from 0° to 40°, the central wavelength shift range of the passband band is between 12nm and 20nm; within the range from 0° to 10°, the incident angle With a change of 1°, the central wavelength shift of the passband band is less than 8nm.

According to an embodiment of the present invention, the bandwidth of the passband band is less than 400 nm. In this embodiment, in the wavelength range of 800-1200 nm, the transmittance in the passband band is greater than 90%, and the transmittance in the cutoff band is less than 0.1%. Referring to FIG. 2 , in this embodiment, the steepness of the curves on the UV side (near the short wavelength side) and IR side (near the long wavelength side) of the passband band ranges from 7nm to 13nm.

According to an embodiment of the present invention, the first high refractive index film layer 121 is a hydrogenated silicon (Si:H) layer. In this embodiment, within the wavelength range of 800-1200 nm, the refractive index of the first high-refractive index film layer 121 is greater than 3.5, and the extinction coefficient is less than 0.002. Wherein, at the wavelength of 850 nm, the refractive index of the first high refractive index film layer 121 is greater than 3.6. At the wavelength of 940nm, the refractive index of the first high refractive index film layer 121 is greater than 3.55.

According to an embodiment of the present invention, the first high refractive index film layer 121 is a sputtering reaction film layer. In this embodiment, the first high refractive index film layer 121 is plated by sputtering reaction equipment. The material used for the first high refractive index film layer 121 is hydrogen silicide. The substrate 11 with a clean surface is placed in a sputtering reaction device, and the first high-refractive-index film layer 121 is plated on the substrate 11 in the presence of a silicon target and hydrogen gas. In this embodiment, the adjustable flow rate is introduced into the reaction equipment, the sputtering reaction temperature is 80°C-300°C, and the sputtering rate of silicide is 0.1nm/s≤v≤1nm/s. In this embodiment, the flow rate of hydrogen introduction satisfies 10 sccm≦v1≦50 sccm. Through the setting of the above conditions, the plated first high refractive index film layer 121 has good film layer characteristics, so that the first high refractive index film layer 121 reaches a higher refractive index, and further makes the near-infrared narrow-band filtering of the present invention The imaging effect of the film is better.

As shown in FIG. 3 , according to another embodiment of the present invention, a near-infrared narrow-band filter of the present invention includes a substrate 11 , an IR film system 12 and an AR film system 13 . In this embodiment, the IR film system 12 and the AR film system 13 are respectively disposed on opposite sides of the substrate 11 . The IR film system 12 and the AR film system 13 are structures composed of multilayer films respectively. In this embodiment, the IR film system 12 includes first high-refractive-index film layers 121 and first low-refractive-index film layers 122 that are plated alternately. In this embodiment, the refractive index of the first high refractive index film layer 121 is greater than 3, and the refractive index of the first low refractive index film layer 122 is less than 3. In the IR film system 12 , the outermost layer of the IR film system 12 is the first low refractive index film layer 122 . The AR film system 13 includes alternately plated second high-refractive-index film layers 131 and second low-refractive-index film layers 132, the refractive index of the second high-refractive index film layer 131 can be greater than 3 or less than 3, and the second lowest The refractive index of the refractive index film layer 132 is less than 3. It should be pointed out that when the refractive index of the second high refractive index film layer 131 is less than 3, the material used for the second high refractive index film layer 131 is the same as that of the second low refractive index film layer. The materials 132 are different, and the refractive index of the second high refractive index film layer 131 is higher than that of the second low refractive index film layer 132 . In the AR film system 13 , the outermost layer of the AR film system 13 (the position where the AR film system 13 is in contact with the substrate 11 and the incident medium respectively) is the second low refractive index film layer 132 . In this embodiment, the total thickness of the IR film system 12 and the AR film system 13 of the near-infrared narrow-band filter is less than 9.8 μm. In this embodiment, the full width at half maximum of the near-infrared narrow-band filter is less than 120 nm. Further, in this embodiment, the total thickness of the IR film system 12 and the AR film system 13 of the near-infrared narrow-band filter is less than 8 μm. In this embodiment, the full width at half maximum of the near-infrared narrow-band filter is less than 114 nm. By setting the outer sides of the IR film system 12 and the AR film system 13 respectively as the first low refractive index film layer 122 and the second low refractive index film layer 132, it is beneficial for the IR film system 12 and the AR film system 13 to adhere to the substrate 11 , and its hardness is high, wear resistance is good, corrosion resistance is strong, thereby helps to guarantee the structural stability of IR film system 12 and AR film system 13 of the present invention, and improves the service life of IR film system 12 and AR film system 13 , further improving the service life of the infrared narrowband filter of the present invention. At the same time, the thickness of the near-infrared narrow-band filter of the present invention is small, which saves the production cost of the present invention. In this embodiment, the arrangement structure of the IR film system 12 is consistent with the foregoing embodiments, and will not be repeated here.

It should be pointed out that the IR film is an infrared cut-off film, and the AR film is an anti-reflection film, that is, an anti-reflection film.

According to an embodiment of the present invention, the refractive index of the second low refractive index film layer 132 is less than 3. In this embodiment, the material of the second low refractive index film layer 132 is SiO ₂ , Nb ₂ O ₅ , Ta ₂ O ₅ , TiO ₂ , Al ₂ O ₃ , ZrO ₂ , Pr ₆ O ₁₁ , La ₂ O ₃ , Si ₂ N, SiN, Si ₂ N ₃ , Si ₃ N ₄ or a combination of one or more.

According to one embodiment of the present invention, in the wavelength range of 350-1200nm, since the AR film system 13 is alternately coated with the second high refractive index film layer 131 and the second low refractive index film layer 132, the incident light Interference effects thus create passband regions and cutoff regions. In this embodiment, the AR film system 13 has a passband region with a transmittance greater than 90%, and a cutoff region with a transmittance of less than 0.1%. In this embodiment, within the wavelength range of 800-1200 nm, the transmittance of the transition region in the AR film system 13 is between 0.1%-90%.

As shown in FIG. 4 , according to an embodiment of the present invention, the infrared imaging system of the present invention includes an IR emitting system and an IR receiving system. In this embodiment, the IR emitting system includes an IR emitting light source 2 and a first lens assembly 3 . The first lens assembly 3 is arranged opposite to the IR emitting light source 2, and the first lens assembly 3 is used to transmit the light emitted by the IR emitting light source 2 and project the transmitted light onto an object A (such as a human face, a hand, etc.). In this embodiment, the IR emitting light source 2 is one of VCSEL, LD, and LED. In this embodiment, the first lens assembly 3 includes an infrared light source collimating lens 31 and a diffraction assembly 32 . In this embodiment, the diffraction component 32 is arranged on the infrared light source collimating lens 31 . The light emitted by the IR emitting light source 2 is corrected and collimated through the infrared light source collimating lens 31 , and the collimated light is projected onto the object through the diffraction component 32 .

According to an embodiment of the present invention, the IR receiving system includes a near-infrared narrow-band filter 1 , a second lens assembly 4 and an infrared image sensor 5 . In this embodiment, the infrared narrowband filter 1 is located between the second lens assembly 4 and the infrared image sensor 5 . The second lens assembly 4 can be an ordinary lens. The light on the object is transmitted to the second lens assembly 4, and the light received by the second lens assembly 4 is transmitted to the infrared narrow-band filter 1, and the light is projected onto the infrared image sensor 5 through the action of the infrared narrow-band filter 1 for imaging. In this embodiment, the infrared image sensor 5 is a 3D infrared image sensor. In this embodiment, the infrared image sensor 5 combines the spatial information collected by the second lens assembly 4 and The color information collected by the lens imaging end is combined to generate a 3D image with spatial information for face recognition, gesture recognition, etc.

In order to further illustrate the present invention, the near-infrared narrow-band filter of the present invention is illustrated.

Example 1:

The first high-refractive-index film layer 121 and the first low-refractive-index film layer 122 are alternately plated to form an IR film system of a near-infrared narrow-band filter. In this embodiment, the first high refractive index film layer 121 is made of hydrogenated silicon (Si:H) material, and the first low refractive index film layer 122 is made of silicon nitride (ie SiN) material, alternately in the form of L(HL) ^m Arrange to form the filter IR band-pass film system; wherein, L represents the height of the first low refractive index film layer 122 with a thickness of 1/4 reference wavelength, and H represents the thickness of the first high refractive index film layer 121 with a reference wavelength of 1/4 The height, m represents the number of alternate plating.

In this embodiment, within the range where the incident angle changes from 0° to 10°, the central wavelength shift range of the passband band is between 0.5nm and 1.5nm, and every time the incident angle changes by 1°, the center wavelength of the passband band The amplitude of wavelength shift is less than 1.5nm.

In this embodiment, within the range where the incident angle changes from 0° to 20°, the central wavelength shift amplitude of the passband band is between 2.5nm and 8nm, and within the range where the incident angle changes from 10° to 20°, the incident angle For every 1° change, the central wavelength shift of the passband band is less than 6nm.

In this embodiment, within the range where the incident angle changes from 0° to 30°, the central wavelength shift range of the passband band is between 8nm and 12nm, and within the range where the incident angle changes from 20° to 30°, every With a change of 1°, the central wavelength shift of the passband band is less than 5nm.

In this embodiment, when the incident angle changes from 0° to 40°, the central wavelength shift range of the passband band is between 12nm and 20nm; within the range from 0° to 10°, the incident angle With a change of 1°, the central wavelength shift of the passband band is less than 8nm.

By using the following calculation formula:

OT _i =OT ₀ (1+Acos(2×pi×f×i)sin(2×pi×f×i)),

Among them, OT _i represents the optical thickness of the i-th film layer, OT ₀ represents the optical thickness of a quarter of the design wavelength, pi represents the circumference ratio, and f represents the modulation factor, which is between 0 and 1.

Substitute into the equation:

The obtained film layer parameters are as follows:

1 2 3 4 5 film material SiN Si:H SiN Si:H SiN Thickness/nm 30 232.89 152.83 118.43 73.61 6 7 8 9 10 film material Si:H SiN Si:H SiN Si:H Thickness/nm 82.67 110.81 125.06 143.63 241.24 11 12 13 14 15 film material SiN Si:H SiN Si:H SiN Thickness/nm 79.48 150.7 56.18 232.67 103.84 16 17 18 19 20 film material Si:H SiN Si:H SiN Si:H Thickness/nm 244.31 313.36 272.26 76.29 73.39 twenty one twenty two twenty three twenty four 25 film material SiN Si:H SiN Si:H SiN Thickness/nm 371.49 84.72 26.21 288.09 122.32 26 27 28 29 30 film material Si:H SiN Si:H SiN Si:H Thickness/nm 66.8 382.21 142.68 191.9 262.73 31 32 33 34 35 film material SiN Si:H SiN Si:H SiN Thickness/nm 118.05 64.98 376.7 167.58 27.7

Table 1

As shown in Figure 5, and through the above calculation results (that is, the thickness of the IR film system represented in Table 1, that is, the physical thickness of the IR film system plating, unit: nm), in this embodiment, when the IR film layer is passed through Under the condition of the ratio of m=17, the total thickness of the IR film system is 5.61 μm, so that the thickness of the IR film system of the present invention meets the design requirements, and it also ensures that the passband of the IR film system under the conditions of different incident angles The central wavelength drift on the band also meets the above design requirements, and the IR film has a passband in the range of 800-1200nm, and the transmittance is greater than 90%; the bandwidth of the passband is less than 120nm; there is one on each side of the passband In the cut-off band, the transmittance is less than 0.1%, and the lower transmittance can be less than 0.001%, which ensures the imaging quality of the near-infrared filter of the present invention.

Example 2:

The first high-refractive-index film layer 121 and the first low-refractive-index film layer 122 are alternately plated to form an IR film system of a near-infrared narrow-band filter. In this embodiment, the first high refractive index film layer 121 is made of hydrogenated silicon (Si:H) material, and the first low refractive index film layer 122 is made of silicon nitride (ie Si ₃ N ₄ ) material. ^m forms are alternately arranged to form the filter IR bandpass film system; wherein, L represents the thickness of the first low refractive index film layer 122 at 1/4 of the reference wavelength, and H represents the thickness of the first high refractive index film layer 121 at 1/4 Referring to the height of the wavelength thickness, m represents the number of times of alternate plating.

In this embodiment, within the range where the incident angle changes from 0° to 10°, the central wavelength shift range of the passband band is between 0.5nm and 1.5nm, and every time the incident angle changes by 1°, the center wavelength of the passband band The amplitude of wavelength shift is less than 1.5nm.

In this embodiment, within the range of the incident angle changing from 0° to 20°, the central wavelength shift amplitude of the passband band is between 2.5nm and 8nm, and within the range of changing from 10° to 20°, the incident angle For every 1° change, the central wavelength shift of the passband band is less than 6nm.

In this embodiment, within the range where the incident angle changes from 0° to 30°, the center wavelength shift range of the passband band is between 8nm and 12nm, and within the range where the incident angle changes from 20° to 30°, every With a change of 1°, the central wavelength shift of the passband band is less than 5nm.

In this embodiment, when the incident angle changes from 0° to 40°, the central wavelength shift range of the passband band is between 12nm and 20nm; within the range from 0° to 10°, the incident angle With a change of 1°, the central wavelength shift of the passband band is less than 8nm.

By using the following calculation formula:

OT _i =OT ₀ (1+Acos(2×pi×f×i)sin(2×pi×f×i)),

Among them, OT _i represents the optical thickness of the i-th film layer, OT ₀ represents the optical thickness of a quarter of the design wavelength, pi represents the circumference ratio, and f represents the modulation factor, which is between 0 and 1.

Substitute into the equation:

The obtained film layer parameters are as follows:

1 2 3 4 5 film material Si3N4 Si:H Si3N4 Si:H Si3N4 film thickness 234.05 73.12 193.41 79.58 113.2 6 7 8 9 10 film material Si:H Si3N4 Si:H Si3N4 Si:H film thickness 196.33 111.74 100.62 86 115.42 11 12 13 14 15 film material Si3N4 Si:H Si3N4 Si:H Si3N4 film thickness 107 64.44 112.56 64.98 107.61 16 17 18 19 20 film material Si:H Si3N4 Si:H Si3N4 Si:H film thickness 128.77 64.31 87.54 111.36 199.79 twenty one twenty two twenty three twenty four 25 film material Si3N4 Si:H Si3N4 Si:H Si3N4 film thickness 114.06 151.56 63.51 277.82 109.72 26 27 28 29 30 film material Si:H Si3N4 Si:H Si3N4 Si:H film thickness 66.15 106.45 365 340.12 78.77 31 32 33 34 35 film material Si3N4 Si:H Si3N4 Si:H Si3N4 film thickness 110.3 226.9 110.56 95.19 45.38

Table 2

As shown in Figure 6, and through the above calculation results (that is, the thickness of the IR film system represented in Table 2, that is, the physical thickness of the IR film system plating, unit: nm), in this embodiment, when the IR film layer is satisfied Under the condition of the ratio of m=17, the total thickness of the IR film system is 4.62 μm, so that the thickness of the IR film system of the present invention meets the design requirements, and it also ensures that the passband of the IR film system under the conditions of different incident angles The central wavelength drift on the band also meets the above design requirements, and the IR film has a passband in the range of 800-1200nm, and the transmittance is greater than 90%; the bandwidth of the passband is less than 120nm; there is one on each side of the passband In the cut-off band, the transmittance is less than 0.1%, and the lower transmittance can be less than 0.001%, which ensures the imaging quality of the near-infrared filter of the present invention.

Example 3:

The first high-refractive-index film layer 121 and the first low-refractive-index film layer 122 are alternately plated to form an IR film system of a near-infrared narrow-band filter. In this embodiment, the first high refractive index film layer 121 is made of hydrogenated silicon (Si:H) material, and the first low refractive index film layer 122 is made of mixed materials, such as silicon nitride (SiN) and silicon dioxide (SiO ₂ ) Mixed materials, or silicon nitride (ie SiN and Si ₃ N ₄ ) mixed materials, alternately arranged in the form of L(HL) ^m to form an IR band-pass film system for filters; where L represents the first low refractive index film The height of the layer 122 is 1/4 of the reference wavelength thickness, H represents the height of the first high refractive index film layer 121 of 1/4 reference wavelength thickness, and m represents the number of times of alternate plating.

In this embodiment, within the range where the incident angle changes from 0° to 10°, the central wavelength shift range of the passband band is between 0.5nm and 1.5nm, and every time the incident angle changes by 1°, the center wavelength of the passband band The amplitude of wavelength shift is less than 1.5nm.

In this embodiment, within the range where the incident angle changes from 0° to 20°, the central wavelength shift amplitude of the passband band is between 2.5nm and 8nm, and within the range where the incident angle changes from 10° to 20°, the incident angle For every 1° change, the central wavelength shift of the passband band is less than 6nm.

In this embodiment, within the range where the incident angle changes from 0° to 30°, the center wavelength shift range of the passband band is between 8nm and 12nm, and within the range where the incident angle changes from 20° to 30°, every With a change of 1°, the central wavelength shift of the passband band is less than 5nm.

In this embodiment, when the incident angle changes from 0° to 40°, the central wavelength shift range of the passband band is between 12nm and 20nm; within the range from 0° to 10°, the incident angle With a change of 1°, the central wavelength shift of the passband band is less than 8nm.

By using the following calculation formula:

OT _i =OT ₀ (1+Acos(2×pi×f×i)sin(2×pi×f×i)),

Among them, OT _i represents the optical thickness of the i-th film layer, OT ₀ represents the optical thickness of a quarter of the design wavelength, pi represents the circumference ratio, and f represents the modulation factor, which is between 0 and 1.

Substitute into the equation:

The obtained film layer parameters are as follows:

table 3

As shown in Figure 7, and through the above calculation results (that is, the thickness of the IR film system represented in Table 3, that is, the physical thickness of the IR film system plating, unit: nm, and Mixture represents the mixed material), in this embodiment, in Under the condition of satisfying the transmittance of the IR film layer, m=16 is taken, and the total thickness of the IR film system is 5.11 μm, so that the thickness of the IR film system of the present invention meets the design requirements, and it also ensures that under the conditions of different incident angles , the central wavelength drift on the passband band of the IR film system also meets the above design requirements, and the IR film system has a passband band in the range of 800-1200nm, and the transmittance is greater than 90%; the bandwidth of the passband band is less than 120nm; There is a cut-off band on both sides, and its transmittance is less than 0.1%, and the lower transmittance can be less than 0.001%, which ensures the imaging quality of the near-infrared filter of the present invention.

Example 4:

The first high-refractive-index film layer 121 and the first low-refractive-index film layer 122 are alternately plated to form an IR film system of a near-infrared narrow-band filter. In this embodiment, the first high refractive index film layer 121 is made of hydrogenated silicon (Si:H) material, and the first low refractive index film layer 122 is made of silicon dioxide (SiO ₂ ) material, alternately in the form of (LH) ^m L Arrange to form the filter IR band-pass film system; wherein, L represents the height of the first low refractive index film layer 122 with a thickness of 1/4 reference wavelength, and H represents the thickness of the first high refractive index film layer 121 with a reference wavelength of 1/4 The height, m represents the number of alternate plating.

The second high-refractive-index film layer 131 and the second low-refractive-index film layer 132 are alternately plated to form an AR film system of a near-infrared narrow-band filter. In this embodiment, the second high refractive index film layer 131 is made of niobium pentoxide (Nb ₂ O ₅ ) material, and the second low refractive index film layer 132 is made of silicon dioxide (SiO ₂ ) material (it should be noted that Since the refractive index of niobium pentoxide (Nb ₂ O ₅ ) is higher than that of silicon dioxide (SiO ₂ ), niobium pentoxide (Nb ₂ O ₅ ) can also be used as the second high refractive index film layer 131. material.), alternately arranged in the form of (LH) ^s L to form the filter AR bandpass film system; wherein, L represents the height of the second low refractive index film layer 132 with a thickness of 1/4 reference wavelength, and H represents the second highest The thickness of the refractive index film layer 131 is 1/4 of the reference wavelength, and s represents the number of times of alternate plating.

In this embodiment, within the range where the incident angle changes from 0° to 10°, the central wavelength shift range of the passband band is between 0.5nm and 1.5nm, and every time the incident angle changes by 1°, the center wavelength of the passband band The amplitude of wavelength shift is less than 1.5nm.

In this embodiment, within the range where the incident angle changes from 0° to 20°, the central wavelength shift amplitude of the passband band is between 2.5nm and 8nm, and within the range where the incident angle changes from 10° to 20°, the incident angle For every 1° change, the central wavelength shift of the passband band is less than 6nm.

In this embodiment, within the range where the incident angle changes from 0° to 30°, the center wavelength shift range of the passband band is between 8nm and 12nm, and within the range where the incident angle changes from 20° to 30°, every With a change of 1°, the central wavelength shift of the passband band is less than 5nm.

In this embodiment, when the incident angle changes from 0° to 40°, the central wavelength shift range of the passband band is between 12nm and 20nm; within the range from 0° to 10°, the incident angle With a change of 1°, the central wavelength shift of the passband band is less than 8nm.

By using the following calculation formula:

OT _i =OT ₀ (1+Acos(2×pi×f×i)sin(2×pi×f×i)),

Among them, OT _i represents the optical thickness of the i-th film layer, OT ₀ represents the optical thickness of a quarter of the design wavelength, pi represents the circumference ratio, and f represents the modulation factor, which is between 0 and 1.

Substitute into the equation:

The obtained film parameters are as follows:

Table 4

1 2 3 4 5 Material SiO ₂ Nb ₂ O ₅ SiO ₂ Nb ₂ O ₅ SiO ₂ Thickness (nm) 177.36 29.01 86.24 34.26 137.61 6 7 8 9 10 Material Nb ₂ O ₅ SiO ₂ Nb ₂ O ₅ SiO ₂ Nb ₂ O ₅ Thickness (nm) 42.57 105.57 32.63 124.57 39.38 11 12 13 14 15 Material SiO ₂ Nb ₂ O ₅ SiO ₂ Nb ₂ O ₅ SiO ₂ Thickness (nm) 127.56 36.38 121.12 36.38 123.16 16 17 18 19 20 Material Nb ₂ O ₅ SiO ₂ Nb ₂ O ₅ SiO ₂ Nb ₂ O ₅ Thickness (nm) 31.7 132.74 44.2 128.03 27.69 twenty one twenty two twenty three twenty four 25 Material SiO ₂ Nb ₂ O ₅ SiO ₂ Nb ₂ O ₅ SiO ₂ Thickness (nm) 110.12 44.01 131.96 36.76 76.98

table 5

Shown in conjunction with Fig. 8 and Fig. 9, and through above-mentioned calculation result (being the physical thickness (unit: nm) of the IR film system coating of representative IR film thickness in Table 4 and the AR film thickness of representative in Table 5 namely AR film system plated physical thickness (unit: nm)), in the present embodiment, under the condition that satisfies IR film transmittance and AR film transmittance, get m=15, s=12, IR The total thicknesses of the film system and the AR film system are 5.19 μm and 2.02 μm respectively, so that the thicknesses of the IR film system and the AR film system of the present invention all meet the design requirements, and at the same time ensure that the IR film system is The central wavelength drift on the passband band also meets the above design requirements, and the IR film has a passband band in the range of 800-1200nm, and the transmittance is greater than 90%; the bandwidth of the passband band is less than 400nm; there are 2 cut-off bands, On both sides of the passband, the transmittance is less than 0.1%. The AR film system has a passband area and a cut-off area in the range of 350-1200nm, and the transmittance is greater than 90% and less than 0.1%. There is a transition region, and the transmittance is between 0.1% and 90%, which ensures the imaging quality of the near-infrared filter of the present invention.

Example 5:

The first high-refractive-index film layer 121 and the first low-refractive-index film layer 122 are alternately plated to form an IR film system of a near-infrared narrow-band filter. In this embodiment, the first high refractive index film layer 121 is made of hydrogenated silicon (Si:H) material, and the first low refractive index film layer 122 is made of silicon dioxide (SiO ₂ ) material, alternately in the form of (LH) ^m L Arrange to form the filter IR band-pass film system; wherein, L represents the height of the first low refractive index film layer 122 with a thickness of 1/4 reference wavelength, and H represents the thickness of the first high refractive index film layer 121 with a reference wavelength of 1/4 The height, m represents the number of alternate plating.

The second high-refractive-index film layer 131 and the second low-refractive-index film layer 132 are alternately plated to form an AR film system of a near-infrared narrow-band filter. In this embodiment, the second high refractive index film layer 131 is made of hydrogenated silicon (Si:H) material, and the second low refractive index film layer 132 is made of silicon dioxide (SiO ₂ ) material, alternately in the form of (LH) ^s L Arrange to form the filter AR band-pass film system; wherein, L represents the height of the second low refractive index film layer 132 with a thickness of 1/4 reference wavelength, and H represents the thickness of the second high refractive index film layer 131 with a reference wavelength of 1/4 The high, s represents the number of alternate plating.

In this embodiment, within the range where the incident angle changes from 0° to 10°, the central wavelength shift range of the passband band is between 0.5nm and 1.5nm, and every time the incident angle changes by 1°, the center wavelength of the passband band The amplitude of wavelength shift is less than 1.5nm.

In this embodiment, within the range where the incident angle changes from 0° to 20°, the central wavelength shift amplitude of the passband band is between 2.5nm and 8nm, and within the range where the incident angle changes from 10° to 20°, the incident angle For every 1° change, the central wavelength shift of the passband band is less than 6nm.

In this embodiment, within the range where the incident angle changes from 0° to 30°, the central wavelength shift range of the passband band is between 8nm and 12nm, and within the range where the incident angle changes from 20° to 30°, every With a change of 1°, the central wavelength shift of the passband band is less than 5nm.

In this embodiment, when the incident angle changes from 0° to 40°, the central wavelength shift range of the passband band is between 12nm and 20nm; within the range from 0° to 10°, the incident angle With a change of 1°, the central wavelength shift of the passband band is less than 8nm.

By using the following calculation formula:

OT _i =OT ₀ (1+Acos(2×pi×f×i)sin(2×pi×f×i)),

Among them, OT _i represents the optical thickness of the i-th film layer, OT ₀ represents the optical thickness of a quarter of the design wavelength, pi represents the circumference ratio, and f represents the modulation factor, which is between 0 and 1.

Substitute this into the equation:

The obtained film parameters are as follows:

Table 6

1 2 3 4 5 film material SiO2 Si:H SiO2 Si:H SiO2 film thickness 118.99 144.41 121.91 40.98 99.76 6 7 8 9 10 film material Si:H SiO2 Si:H SiO2 Si:H film thickness 38.13 108.77 46.76 96.72 40 11 12 13 14 15 film material SiO2 Si:H SiO2 Si:H SiO2 film thickness twenty one 105 114.2 162.36 134.9 16 17 18 19 20 film material Si:H SiO2 Si:H SiO2 Si:H film thickness 20 20 20 86.73 41.24 twenty one twenty two twenty three twenty four 25 film material SiO2 Si:H SiO2 Si:H SiO2 film thickness 117.94 60.05 45.65 53.89 139.6

Table 7

Shown in conjunction with Fig. 10 and Fig. 11, and through the above-mentioned calculation result (that is, the physical thickness (unit: nm) of the IR film system plating of the IR film thickness represented in Table 6 and the AR film thickness represented in Table 7 are AR film system plated physical thickness (unit: nm)), in the present embodiment, under the condition that satisfies IR film layer transmittance and AR film layer transmittance, get m=10, s=12, IR The total thicknesses of the film system and the AR film system are 3.16 μm and 2 μm respectively, so that the thicknesses of the IR film system and the AR film system of the present invention all meet the design requirements, and the IR film system has a passband band in the range of 800-1200 nm, The transmittance is greater than 90%; the bandwidth of the pass band is less than 400nm; there are 2 cut-off bands, which are respectively on both sides of the pass band, and the transmittance is less than 0.1%. A cut-off area, the transmittance is greater than 90% and less than 0.1% respectively; there is a transition area between 800 and 1200, the transmittance is between 0.1% and 90%, and it also ensures that under the conditions of different incident angles, The central wavelength shift amplitude in the passband band of the IR film system also meets the above design requirements, which ensures the imaging quality of the near-infrared filter of the present invention.

The above content is only an example of the specific solutions of the present invention. For the equipment and structures not described in detail therein, it should be understood that they are implemented by adopting the existing general equipment and general methods in the art.

The above description is only a solution of the present invention, and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (18)

1. a kind of near-infrared narrow band filter, which is characterized in that including：Substrate (11) is arranged in the substrate (11) side IR membrane system (12)；

The IR membrane system (12) includes the first high refractive index layer (121) and the first low-index film (122) being alternately coated with, The outermost layer of the IR membrane system (12) is the first low-index film (122)；In the wave-length coverage of 800~1200nm, institute IR membrane system (12) are stated with a passband wave band, two transition wave bands and two cut-off wave bands, the passband wave band is located at two Between described two cut-off wave bands, the little bellow section is between the passband wave band and the cut-off wave band；

The passband wave band has central wavelength, and in the range of incidence angle changes from 0 ° to 30 °, in the passband wave band Heart wave length shift amplitude is between 7nm~13nm.

2. near-infrared narrow band filter according to claim 1, which is characterized in that change from 20 ° to 30 ° in incidence angle In range, every 1 ° of the variation of incidence angle, the central wavelength drift band of the passband wave band is less than 5nm.

3. near-infrared narrow band filter according to claim 2, which is characterized in that the passband band is less than 400nm。

4. near-infrared narrow band filter according to claim 3, which is characterized in that in the wave-length coverage of 800~1200nm Interior, the passband wave band transmitance is greater than 90%, and the cut-off wave band transmitance is less than 0.1%.

5. near-infrared narrow band filter according to claim 4, which is characterized in that the side passband wave band UV and IR lateral curvature Line steepness is between 7nm~13nm.

6. near-infrared narrow band filter according to any one of claims 1 to 5, which is characterized in that first high refractive index Film layer (121) is layer of hydrogenated；

In the wave-length coverage of 800~1200nm, the refractive index of first high refractive index layer (121) is greater than 3.5, and delustring Coefficient is less than 0.002.

7. near-infrared narrow band filter according to claim 6, which is characterized in that at 850nm wavelength, described first is high Refractivity film layer (121) refractive index is greater than 3.6；

At 940nm wavelength, the first high refractive index layer (121) refractive index is greater than 3.55.

8. near-infrared narrow band filter according to claim 6, which is characterized in that first high refractive index layer It (121) is sputtering reaction film layer, in the presence of hydrogen, sputtering reaction temperature is 80 DEG C~300 DEG C, and sputter rate is 0.1nm/s≤v≤1nm/s。

9. near-infrared narrow band filter according to claim 8, which is characterized in that the hydrogen is drawn with adjustable flow Enter, and its flow meets 10sccm≤v1≤50sccm.

10. according to claim 1 or near-infrared narrow band filter described in 9, which is characterized in that first high refractive index layer (121) meet with the physical thickness relationship of first low-index film (122)：0.01≤D_L/D_H≤ 100, wherein D_L、D_H Respectively indicate the physical thickness of the first low-index film and the first high refractive index layer.

11. near-infrared narrow band filter according to claim 1, which is characterized in that change from 0 ° to 10 ° in incidence angle In range, the central wavelength drift band of the passband wave band is between 0.5nm~1.5nm, and every 1 ° of the variation of incidence angle is described The central wavelength drift band of passband wave band is less than 1.5nm；

In the range of incidence angle changes from 0 ° to 20 °, the central wavelength drift band of the passband wave band between 2.5nm~ Between 8nm, change from 10 ° in the range of 20 °, every 1 ° of the variation of incidence angle, the central wavelength drift band of the passband wave band Less than 6nm；

In the range of incidence angle changes from 0 ° to 40 °, the central wavelength drift band of the passband wave band between 12nm~ Between 20nm, change from 0 ° in the range of 10 °, every 1 ° of the variation of incidence angle, the central wavelength drift band of the passband wave band Less than 8nm.

12. near-infrared narrow band filter according to claim 1, which is characterized in that further include AR membrane system (13)；

The IR membrane system (12) and the opposite two sides positioned at the substrate (11) of the AR membrane system (13)；

The AR membrane system (13) includes the second high refractive index layer (131) and the second low-index film (132) being alternately coated with, The outermost layer of the AR membrane system (13) is the second low-index film (132).

13. near-infrared narrow band filter according to claim 12, which is characterized in that in the wavelength model of 350~1200nm In enclosing, the AR membrane system (13) has a pass band areas, and its transmitance is greater than 90%, a cut-off region, and it is penetrated Rate is less than 0.1%；

In the wave-length coverage of 800~1200nm, the AR membrane system (13) also have a transitional region, and its transmitance between Between 0.1%~90%.

14. near-infrared narrow band filter according to claim 12 or 13, which is characterized in that the IR membrane system (12) and institute The film layer overall thickness of AR membrane system (13) is stated less than 9.8 μm.

15. near-infrared narrow band filter according to claim 14, which is characterized in that the near-infrared narrow band filter Full width at half maximum value is less than 120nm.

16. near-infrared narrow band filter according to claim 12 or 13, which is characterized in that first low refractive index film The refractive index of layer (122) is less than 3, and its material is SiO₂、Nb₂O₅、Ta₂O₅、TiO₂、Al₂O₃、ZrO₂、Pr₆O₁₁、La₂O₃、Si₂N、 SiN、Si₂N₃、Si₃N₄One of or a variety of combinations；

The refractive index of second low-index film (132) is less than 3, and its material is SiO₂、Nb₂O₅、Ta₂O₅、TiO₂、 Al₂O₃、ZrO₂、Pr₆O₁₁、La₂O₃、Si₂N、SiN、Si₂N₃、Si₃N₄One of or a variety of combinations.

17. a kind of infrared imaging system using any near-infrared narrow band filter of claim 1 to 16, feature exist In, including IR emission system and IR reception system；

The IR emission system includes the first of IR transmitting light source (2) and the light for projecting IR transmitting light source (2) sending Lens assembly (3)；

It includes near-infrared narrow band filter (1), the second lens assembly (4) and infrared image sensor (5) that the IR, which receives system,；

The infrared narrow band filter (1) is between second lens assembly (4) and the infrared image sensor (5).

18. infrared imaging system according to claim 17, which is characterized in that first lens assembly (3) includes red Outer light source collimates the diffraction component (32) of camera lens (31) and setting on infrared light supply collimation camera lens (31).