CN118837997B - A multi-channel silicon-based wavelength division multiplexing 90-degree optical mixing chip - Google Patents
A multi-channel silicon-based wavelength division multiplexing 90-degree optical mixing chip Download PDFInfo
- Publication number
- CN118837997B CN118837997B CN202411219291.3A CN202411219291A CN118837997B CN 118837997 B CN118837997 B CN 118837997B CN 202411219291 A CN202411219291 A CN 202411219291A CN 118837997 B CN118837997 B CN 118837997B
- Authority
- CN
- China
- Prior art keywords
- waveguide
- output
- input
- waveguides
- degree optical
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/10—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type
- G02B6/12—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type of the integrated circuit kind
- G02B6/12007—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type of the integrated circuit kind forming wavelength selective elements, e.g. multiplexer, demultiplexer
- G02B6/12009—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type of the integrated circuit kind forming wavelength selective elements, e.g. multiplexer, demultiplexer comprising arrayed waveguide grating [AWG] devices, i.e. with a phased array of waveguides
- G02B6/12019—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type of the integrated circuit kind forming wavelength selective elements, e.g. multiplexer, demultiplexer comprising arrayed waveguide grating [AWG] devices, i.e. with a phased array of waveguides characterised by the optical interconnection to or from the AWG devices, e.g. integration or coupling with lasers or photodiodes
- G02B6/12021—Comprising cascaded AWG devices; AWG multipass configuration; Plural AWG devices integrated on a single chip
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/10—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type
- G02B6/12—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type of the integrated circuit kind
- G02B6/122—Basic optical elements, e.g. light-guiding paths
- G02B6/124—Geodesic lenses or integrated gratings
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/24—Coupling light guides
- G02B6/26—Optical coupling means
- G02B6/28—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals
- G02B6/293—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means
- G02B6/29304—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means operating by diffraction, e.g. grating
- G02B6/29316—Light guides comprising a diffractive element, e.g. grating in or on the light guide such that diffracted light is confined in the light guide
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/24—Coupling light guides
- G02B6/26—Optical coupling means
- G02B6/28—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals
- G02B6/293—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means
- G02B6/29379—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means characterised by the function or use of the complete device
- G02B6/2938—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means characterised by the function or use of the complete device for multiplexing or demultiplexing, i.e. combining or separating wavelengths, e.g. 1xN, NxM
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/0147—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on thermo-optic effects
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Nonlinear Science (AREA)
- Engineering & Computer Science (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Optical Integrated Circuits (AREA)
- Optical Communication System (AREA)
Abstract
本发明公开了一种多通道硅基波分复用90度光混频芯片，该硅基波分复用90度光混频芯片包括：信号光输入波导、本振光输入波导、一个90度光混频器、四个阵列波导光栅(AWG)和输出波导，其中90度光混频器和四个AWG均设有加热电极。信号光和本振光在90度光混频器中进行相干混频，形成一组同相信号和一组正交信号，其中90度光混频器的同相信号输出端分别与AWG1和AWG4的输入端相连，正交信号输出端分别与AWG2和AWG3的输入端相连，四个AWG的输出波导与光纤阵列进行耦合。本发明基于90度光混频器、阵列波导光栅和热移相器，实现了对90度混频信号的波分复用，具有相位不均衡度低、插损小、工作波长可调等优点，可以对使用QPSK，QAM等方式调制的数据进行相干解调。
The present invention discloses a multi-channel silicon-based wavelength division multiplexing 90-degree optical mixing chip, which includes: a signal light input waveguide, a local oscillator light input waveguide, a 90-degree optical mixer, four array waveguide gratings (AWGs) and an output waveguide, wherein the 90-degree optical mixer and the four AWGs are provided with heating electrodes. The signal light and the local oscillator light are coherently mixed in the 90-degree optical mixer to form a group of in-phase signals and a group of orthogonal signals, wherein the in-phase signal output end of the 90-degree optical mixer is respectively connected to the input end of AWG1 and AWG4, the orthogonal signal output end is respectively connected to the input end of AWG2 and AWG3, and the output waveguides of the four AWGs are coupled to the optical fiber array. The present invention is based on a 90-degree optical mixer, an arrayed waveguide grating and a thermal phase shifter, realizes wavelength division multiplexing of a 90-degree mixing signal, has the advantages of low phase imbalance, small insertion loss, adjustable working wavelength, etc., and can perform coherent demodulation on data modulated by QPSK, QAM and the like.
Description
Technical Field
The invention relates to the field of optical communication, in particular to a multichannel silicon fundamental wave division multiplexing 90-degree optical mixing chip.
Background
With the increasing data traffic from video streaming, artificial intelligence, and data cloud service applications, backbone network devices tend to support higher-rate, larger-bandwidth long-distance transmissions. In recent years, coherent optical communication technology has been paid attention to, and compared with a conventional communication transmission system, the coherent optical communication system has higher spectral efficiency and receiver sensitivity, and becomes a key technology for solving a bottleneck of data transmission. As an important component of a coherent optical communication system, a 90-degree optical mixer has been widely deployed in long-distance coherent optical communication networks using modulation schemes such as Quadrature Phase Shift Keying (QPSK) and Quadrature Amplitude Modulation (QAM). Optical multiplexing refers to a technology for improving data transmission capacity and efficiency by transmitting signals of different dimensions simultaneously in an optical fiber transmission system, and includes dimensions such as polarization, mode, wavelength, and the like. The optical multiplexing technology is introduced into a coherent optical communication network, so that the capacity of the transmitted optical signals can be increased by a plurality of times, and the data transmission efficiency is further improved.
In a coherent optical communication receiving system, signal light and local oscillation light are mixed by 90 degrees by a 90-degree optical mixer, and an in-phase signal and a quadrature signal are output. The in-phase signal and the quadrature signal are subjected to photoelectric conversion and differential amplification through a balance photoelectric detector, sampling and quantization processing are performed through an analog-to-digital converter (ADC), and finally a Digital Signal Processor (DSP) processes the discrete digital sequence after sampling and quantization, so that the functions of signal detection and electric signal amplification are realized.
The optical multiplexing modes widely used at present comprise partial division multiplexing, mode division multiplexing, wavelength division multiplexing and the like. In a polarization division multiplexing coherent receiving system, an optical signal is divided into two mutually orthogonal polarized optical signals by a polarization beam splitter, and the two polarized optical signals are respectively mixed with local oscillation light, so that the capacity of the transmitted optical signal is doubled. The mode division multiplexing coherent receiving system is to separate different modes in the signal light by using a mode division multiplexer, and then to carry out 90-degree optical mixing on the signal light of different modes and the local oscillation light, wherein the transmission capacity is related to the number of modes which can be demultiplexed by the mode division multiplexer, and is generally less than 10. The most widely used and mature optical multiplexing technology is the wavelength division multiplexing technology at present, coarse Wavelength Division Multiplexing (CWDM) can transmit at most 18 wavelengths in a 1271nm to 1611nm spectrum grid, and Dense Wavelength Division Multiplexing (DWDM) can carry 40, 80 and even up to 160 wavelengths, and the multiplexing capability far exceeds that of polarization multiplexing and mode division multiplexing technologies. The use of wavelength division multiplexing technology is a necessary trend of development of ultra-large capacity communication systems, and the combination of coherent detection technology and WDM system is a preferred method for realizing a high-speed coherent optical transmission system of 100Gb/s per channel and above. The technology can also be applied to a microwave photon channelized receiver.
Disclosure of Invention
In order to solve the above problems and further improve the information transmission capacity, the present invention provides a multi-channel wavelength division multiplexing 90-degree optical mixing chip, which can reduce the phase imbalance between the in-phase signal and the quadrature signal output by the 90-degree optical mixer and adjust the center wavelength of the AWG output channel to adapt to different WDM system requirements through thermal tuning.
In order to achieve the above purpose, the present invention adopts the following technical scheme:
A silicon-based wavelength division multiplexing 90-degree optical mixing core comprises a signal light input waveguide, a local oscillation light input waveguide, a 90-degree optical mixer, four array waveguide gratings and output waveguides, wherein the 90-degree optical mixer and the four AWGs are respectively provided with a heating electrode. The signal light and the local oscillation light are subjected to coherent mixing in the 90-degree optical mixer to form two paths of in-phase signals and two paths of quadrature signals, wherein two paths of in-phase signal output ends of the 90-degree optical mixer are respectively connected with input ends of the AWG1 and the AWG4, two paths of quadrature signal output ends are respectively connected with input ends of the AWG2 and the AWG3, and output waveguides of the four AWGs are coupled with the optical fiber array for output.
Optionally, the 90-degree optical mixer includes a signal light input waveguide, a local oscillation light input waveguide, a top 1×2MMI, left and right 2×2 MMIs, a bottom 2×2MMI, 4-way 90-degree curved waveguides connecting the 4 MMIs, and four-way output waveguides, wherein a heating electrode is covered above the 4-way 90-way curved waveguides, the local oscillation light input waveguide is coupled with the top 1×2MMI, the signal light input waveguide is coupled with the bottom 2×2MMI, and the signal light and the local oscillation light are input to the left and right 2×2 MMIs through the four-way 90-degree curved waveguides, so that the signal light and the local oscillation light are mixed in 2×2MMI multimode interference regions at two sides, and the mixed optical signals are respectively led out to the I-way output waveguide and the Q-way output waveguide. The four paths of 90-degree bending waves are provided with heating electrodes, and the phase imbalance degree of the I path and the Q path is reduced through thermal tuning, so that the image rejection ratio is improved, the quality of demodulation signals is improved, the phase compensation by using a more expensive DSP is avoided, and the cost is reduced.
Optionally, the 2×2MMI multimode interference region is optimized. The two-end profile structure of the traditional rectangular multimode interference area is optimized to be parabolic, and the action aims at inhibiting reflection on an input/output interface with relatively sharp MMI edges, so that unnecessary energy loss is reduced, and meanwhile, the insertion loss and power unbalance of the MMI can be well balanced.
Alternatively, the 4-way 90-degree bend waveguides are each composed of 2 nonlinear bend taps, uniformly transition from 0.5 micron wide to 2 micron wide, and then uniformly transition to 0.5 micron wide. The nonlinear flip with gradually changed width is utilized, so that the structure has higher robustness to the manufacturing process, and phase errors caused by manufacturing deviation are reduced, thereby improving the image frequency suppression effect, improving the quality of demodulation signals, avoiding using more expensive DSP to perform phase compensation, and reducing the cost.
Optionally, the AWG includes an input channel waveguide, an input coupler, an array waveguide, an output coupler, and an output channel waveguide. The input and output channel waveguides and the array waveguide of the AWG are bar waveguides, and the FPR is a slab waveguide. The array waveguide area is covered with a heating electrode, and the wavelength of an output channel of the AWG meets the WDM system requirement through thermal tuning.
Optionally, the AWG input coupler includes a path of input channels, a FPR and an array waveguide, where the FPR is composed of a rowland circle and a part of grating circles, the radius of the grating circle is 222.46 microns, the radius of the rowland circle is half of the radius of the grating circle, and under the condition that the diffraction order is kept unchanged, the large-radius grating circle can increase the output waveguide spacing, so that the inter-channel crosstalk is effectively reduced. The input channel TAPER is positioned at one side of the Roland circle, the array waveguide TAPER is distributed on the circumference of the grating circle at equal intervals, the extension line of the array waveguide TAPER is intersected at the central input channel (the center of the grating circle), the array waveguide TAPER is connected with the array waveguide, and the array waveguide is designed into a multimode waveguide with the width of 2 micrometers so as to reduce the phase error caused by process difference, reduce loss and improve the smoothness of an output spectral line.
Optionally, the output coupler includes an array waveguide tip, an FPR and an output channel tip, where the FPR is composed of a rowland circle and a part of a grating circle, the radius of the grating circle is 222.46 microns, the radius of the rowland circle is half of the radius of the grating circle, and under the condition that the diffraction order is kept unchanged, the large-radius grating circle can increase the output waveguide spacing, so that inter-channel crosstalk is effectively reduced. The array waveguide TAPER is distributed on the circumference of the grating circle at equal intervals, the extension line of the array waveguide TAPER is intersected with the central output channel (the center of the grating circle), the output channel TAPER is distributed on the circumference of the Rowland circle at equal intervals, the array waveguide TAPER is connected with the array waveguide, and the array waveguide is designed into a multimode waveguide with the width of 2 micrometers so as to reduce the phase error caused by process difference, reduce loss and improve the smoothness of an output spectral line.
Optionally, the array waveguide is designed as a multimode waveguide with the width of 2 micrometers to improve the process tolerance, and the wiring mode is a saddle-type structure, so that the array waveguide is more compact compared with a Z-type structure. Each array waveguide consists of a straight waveguide, two euler bending waveguides which are tangentially connected with the straight waveguide and arc bending waveguides at two ends, and the insertion loss is reduced by using the euler bending waveguides. The length difference of adjacent array waveguides is introduced in the straight waveguide section.
Alternatively, the central wavelength of the AWG output channel is changed by heating the entire array waveguide region through a thermode by utilizing the thermo-optic effect so as to meet the WDM system requirements. The AWG heating electrode can be formed by connecting two electrodes which are arranged in a snake shape with a common cathode in parallel, so that the heating area is larger, the heating effect is better, and the voltage required by heating can be reduced while the resistance value is ensured to be large enough.
Compared with the prior art, the invention has the following advantages:
1. the traditional rectangular MMI multimode interference region is optimized to be parabolic, and unbalance and loss are reduced.
2. The bent waveguide in the 90-degree optical mixer adopts a nonlinear taper with gradually changed width, so that the tolerance to manufacturing process errors is improved.
3. The heating electrode is arranged at the four-way bent waveguide of the 90-degree optical mixer, the optical path of a certain path is changed by utilizing the thermo-optical effect, and the output phase characteristic of the 90-degree optical mixer is tuned, so that the phase error is further reduced.
4. The designed AWG uses a large-radius grating circle, euler curved waveguide and multimode array waveguide, and has the characteristics of low inter-channel crosstalk, low loss, smooth output spectral line and the like.
5. The AWG array waveguide area is covered with heating electrodes in a serpentine arrangement. The array waveguide area is heated, and the central wavelength of the AWG output channel can be adjusted by utilizing the thermo-optical effect so as to adapt to the requirements of different WDM systems.
6. The multichannel silicon fundamental wave division multiplexing 90-degree optical mixing chip designed by utilizing the combination of the 90-degree optical mixer and the AWG has higher process tolerance, has extremely low power consumption compared with the traditional discrete device, and can be used in equipment such as a microwave photon channelized receiver, a high-speed coherent optical module and the like.
Drawings
Figure 1 is a schematic diagram of a multi-channel silicon fundamental wavelength division multiplexing 90-degree optical mixing chip structure of the invention,
Figure 2 is a schematic diagram of a 90 degree optical mixer according to the present invention,
FIG. 3 is a schematic diagram of the structure of a 2X 2MMI according to the invention,
Figure 4 is a schematic view of the AWG structure of the present invention,
Figure 5 shows a 90 degree optical mixer phase error,
Figure 6 is a graph of the transmission spectrum of an AWG,
Fig. 7 (a) QPSK signal IQ modulation composite spectrum, 7 (b) QPSK signal IQ modulation center wavelength 1.55 μm,
Fig. 8 (a) QAM signal IQ modulation composite spectrum, 8 (b) QAM signal IQ modulation center wavelength 1.55 μm,
Fig. 9 (a) QPSK signal constellation at channel center wavelength 1.55 μm, 9 (b) QPSK signal eye diagram at channel center wavelength 1.55 μm,
Fig. 10 (a) QAM signal constellation at channel center wavelength 1.55 μm, 10 (b) QAM signal eye at channel center wavelength 1.55 μm.
Reference numerals for structural elements in fig. 1:
10 A 90-degree optical mixer is provided,
101. The signal light is input into the waveguide,
102. The local oscillation light is input into the waveguide,
103. The positive electrode output end of the in-phase signal,
104. The positive electrode output end of the orthogonal signal,
105. The output end of the negative electrode of the orthogonal signal,
106. The negative electrode output end is carried out in the same phase,
A first AWG is provided at 20 a,
201 A first AWG output waveguide array,
A second AWG is used, at 30,
301 A second AWG output waveguide array,
A third AWG is shown at 40 and,
401 A third AWG output waveguide array,
A fourth AWG is provided at 50 a,
501 A fourth AWG output waveguide array,
Fig. 2, description of the structural elements with reference numerals:
60 inputs to a1 x 2MMI,
601 A signal light input port,
70 The first 2 x 2MMI,
701. The positive electrode output end of the orthogonal signal,
702. The output end of the negative electrode of the orthogonal signal,
71 A second 2 x 2MMI,
711 A signal light input port,
72 A third 2 x 2MMI,
721. The positive electrode output end of the in-phase signal,
722. The negative electrode output end of the in-phase signal,
80 The waveguide is bent by 90 degrees,
90 A2 x 2MMI multimode interference region structure,
The input end of the 91AWG,
A 92AWG input coupler,
93. The input end of the array waveguide,
94. The array of waveguides is arranged such that,
95. The output end of the array waveguide,
96 The output coupler of the AWG,
97 An AWG output.
Detailed Description
In order to enhance the understanding of the present invention, the present embodiment will be described in detail with reference to the accompanying drawings. Other advantages and effects of the present invention will be readily apparent to those skilled in the art from the present disclosure. The invention may be practiced or carried out in other embodiments that depart from the specific details, and the details of the present description may be modified or varied from the spirit and scope of the present invention.
In describing embodiments of the present invention in detail, the cross-sectional view of the device structure is not partially exaggerated to a general scale for convenience of explanation, and the schematic drawings are only examples and should not limit the scope of the present invention herein. In addition, the three-dimensional dimensions of length, width and depth should be included in actual fabrication.
It should be noted that, the illustrations provided in the present embodiment merely illustrate the basic concept of the present invention by way of illustration, and only the components related to the present invention are shown in the drawings rather than the number, shape and size of the components in actual implementation, and the form, number and proportion of each component in actual implementation may be arbitrarily changed, and the layout of the components may be more complex.
Embodiment 1 referring to fig. 1, a multi-channel silicon fundamental wave multiplexing 90-degree optical mixing chip is shown in fig. 1, and the chip structure schematic diagram of the multi-channel silicon fundamental wave multiplexing 90-degree optical mixing chip is shown in fig. 1, wherein the multi-channel silicon fundamental wave multiplexing 90-degree optical mixing chip is composed of a signal light input waveguide 101, a local oscillation light input waveguide 102, a 90-degree optical mixer 10, four AWGs (20, 30,40, 50) and an output waveguide array (201,301,401,501), wherein the 90-degree optical mixer and the four AWGs are respectively provided with a heating electrode. The signal light and the local oscillation light are coherently mixed in the 90-degree optical mixer 10 to form a group of in-phase signals and a group of quadrature signals, wherein the in-phase signal output ends of the 90-degree optical mixer are respectively connected with the input ends of the AWG20 and the AWG50, the quadrature signal output ends are respectively connected with the input ends of the AWG30 and the AWG40, and the optical signals with different wavelengths are output from different ports of the AWG.
The 90-degree optical mixer is shown in fig. 2, and comprises a signal light input waveguide 711, a local oscillation light input waveguide 601, 1×2MMI60, 32×2 MMIs (70, 71, 72), a curved waveguide 80 for connecting 4 MMIs and a four-way output waveguide (701,702,721,722), wherein the local oscillation light input waveguide is connected with the 1×2MMI input end 601, the signal light input waveguide is connected with the bottom 2×2MMI input end 711, the signal light and the local oscillation light are input into two-sided 2× 2MMI70,72 multimode interference areas through the four-way 90-degree curved waveguide, so that the signal light and the local oscillation light are mixed in the 2×2 MMIs (70, 72) at two sides, the left 2×2MMI72 output ends (721, 722) are connected with the I-way waveguides (103, 106), and the right 2×2MMI70 output ends (701, 702) are connected with the Q-way waveguides (104, 105). Heating electrodes are respectively arranged at the four paths of 90-degree bent waveguides. When in use, the electrode is connected with an external power supply to heat the waveguide, and the refractive index of the waveguide is changed by utilizing the thermo-optical effect so as to change the optical path, thereby realizing the phase tunable function.
As shown in fig. 3, the 2×2mmi optimizes the two-end profile structure of the conventional rectangular multimode interference region into a parabolic shape, takes the center of the 2×2mmi as the origin of coordinates, and the first quadrant boundary function expression is:
y=min([W/2,x0-(4α/L2)x2])
Where W is the width of the 2×2MMI, L is the length of the 2×2MMI, x 0 is the parabolic first order term coefficient, and α is the parabolic second order term coefficient. The MMI90 of this new multimode interference zone structure aims to suppress reflections at relatively sharp-edged input/output interfaces, thereby reducing unnecessary energy loss while allowing good balancing of MMI insertion loss and power imbalance. The local oscillation light and the signal light are mixed by the 90-degree optical mixer 10, two paths of in-phase signals and two paths of quadrature signals are output, and the phase information of the signal light can be demodulated according to the light intensity distribution of the port. In-phase signal p-pole 103 is input to AWG20, in-phase signal n-pole 106 is input to AWG50, quadrature signal p-pole 104 is input to AWG30, and quadrature signal n-pole is input to AWG40.
Fig. 4 is a schematic diagram of an AWG input coupler, where an input end 91 is configured to receive an output optical signal of the 90-degree optical hybrid 10, and optical signals with different wavelengths are diffracted in the FPR of the input coupler 92, and since ports 93 of the array waveguides are located on the circumference of the grating circle, diffracted light with different wavelengths reaches the input end 93 of each array waveguide with the same phase, and the diffracted light propagates independently after being coupled into the array waveguides 94. Since the adjacent array waveguides have a constant length difference, a constant phase difference is obtained after light having a certain wavelength is output from the adjacent array waveguides, a multi-beam interference pattern is formed at the output end of the output coupler 96, and since the phase difference is different for light having different wavelengths, the position of the maximum value of the interference pattern is also different, and by placing the output waveguide 97 at these positions, light having different wavelengths can be output from different waveguides. Finally, the optical signal in the output waveguide 97 is coupled into the optical fiber array for further detection.
Fig. 5 shows the phase error of the silicon-based star 90-degree optical mixer of the present embodiment, which is less than 1 degree in the C-band. Fig. 6 is a schematic diagram showing the characteristics of the silicon-based AWG channel of this embodiment. The AWG loss is less than 3dB, the crosstalk is better than-16 dB, the output channel frequency interval is 200GHz, and the 3dB bandwidth is about 150GHz.
The effect of modulating and demodulating QPKS signals and QAM signals of the system is simulated and verified by using the wavelength division multiplexing 90-degree optical mixing chip in claim 1 to design a signal modulation transmission and demodulation system. Setting the baud rate of the system signal as 50Gbaud, loading QPSK signals and QAM signals on optical carriers with the wavelengths of 1543.6nm, 1545.2nm, 1546.8nm, 1550nm, 1551.6nm, 1553.2nm, 1554.8nm and 1556.4nm and the linewidth of 0.1MHz respectively, adjusting the channel wavelength of the AWG in claim 1 by using a thermode to match the optical carrier wavelength, and transmitting the combined signals into a single mode fiber.
Fig. 7 (a) 7 (b) and fig. 8 (a) 8 (b) show spectral diagrams after IQ conversion and synthesis of QPSK signals and QAM signals, respectively. Wherein each symbol of the QPSK signal represents 2bit data, and each symbol of the QAM signal represents 4bit data. The method comprises the steps of demodulating and wavelength-dividing an input signal by using the wavelength division multiplexing 90-degree optical mixing chip in claim 1, converting the optical signal into an electric signal by using a photoelectric detector and a differential amplifying circuit, and performing the next processing by using an ADC and a DSP. When the center wavelength is 1550nm, the demodulated QPSK signal, QAM signal constellation diagram and eye diagram are shown in fig. 9 (a) (b) and fig. 10 (a) (b), respectively, because the 90-degree optical mixer has phase errors, the signal point in the constellation diagram slightly changes and appears as offset in the horizontal and vertical directions, and because the AWG is Gaussian channel filtering, the signal is slightly distorted and the round shape under ideal conditions becomes water drop shape. The simulation results show that the Bit Error Rate (BER) of 8 channels is close to 0, and the coherent demodulation can be efficiently and accurately realized by using the wavelength division multiplexing 90-degree optical mixing chip of the embodiment.
As described above, the wavelength division multiplexing 90-degree optical mixing chip has the following beneficial effects:
The invention provides a wavelength division multiplexing 90-degree optical mixing chip with low crosstalk, large channel bandwidth and low phase deviation. The invention realizes the 90-degree optical mixing function by utilizing the multimode interference coupler, realizes the wavelength division multiplexing and demultiplexing functions by utilizing the AWG, provides a solution for realizing low-power consumption and high-speed data transmission, and has high industrial utilization value.
The above embodiments are merely illustrative of the principles of the present invention and its effectiveness, and are not intended to limit the invention. Modifications and variations may be made to the above-described embodiments by those skilled in the art without departing from the spirit and scope of the invention. Accordingly, it is intended that all equivalent modifications and variations of the invention be covered by the claims, which are within the ordinary skill of the art, be within the spirit and scope of the present disclosure.
It should be noted that the above-mentioned embodiments are not intended to limit the scope of the present invention, and equivalent changes or substitutions made on the basis of the above-mentioned technical solutions fall within the scope of the present invention as defined in the claims.
Claims (5)
1. The multichannel wavelength division multiplexing 90-degree optical mixing chip is characterized by comprising a signal light input waveguide, a local oscillation light input waveguide, a 90-degree optical mixer, four AWGs and output waveguides, wherein the 90-degree optical mixer and the four AWGs are respectively provided with heating electrodes, the signal light and the local oscillation light are coherently mixed in the 90-degree optical mixer to form a group of in-phase signals and a group of quadrature signals, two paths of in-phase signal output ends of the 90-degree optical mixer are respectively connected with input ends of the AWG1 and the AWG4, two paths of quadrature signal output ends are respectively connected with input ends of the AWG2 and the AWG3, and the AWG output optical signals are coupled into an optical fiber array;
The 90-degree optical mixer comprises 1X 2MMI, 3 2X 2 MMIs, four curved waveguides and four output waveguides, wherein the local oscillation light input waveguide is connected with the 1X 2MMI input end, the signal light input waveguide is connected with the bottom 2X 2MMI input end, the signal light and the local oscillation light are input into 2X 2MMI multimode interference areas on two sides through the four 90-degree curved waveguides, so that the signal light and the local oscillation light are mixed in the 2X 2 MMIs on two sides and respectively led out to an I output waveguide and a Q output waveguide, heating electrodes are respectively arranged at the four 90-degree curved waveguides, and the phase tuning is carried out by utilizing the thermo-optic effect, so that the phase imbalance degree of an I path and a Q path is reduced;
The 2×2MMI comprises two input taps, a multimode interference zone optimized by parabolic boundary and two output taps, wherein the length of the multimode interference zone is 6.5 micrometers, and the width of the multimode interference zone is 2.4 micrometers;
The four-way bent waveguide is used for connecting 4 MMIs, each way of bent waveguide consists of 2 nonlinear bent taps, and the width of the bent waveguide is uniformly transited from 0.5 micron to 2 microns, and then uniformly transited to 0.5 micron.
2. The multi-channel wavelength division multiplexing 90-degree optical mixing chip of claim 1 wherein said AWG comprises an input channel waveguide, an input coupler, an array waveguide, an output coupler, and an output channel waveguide, the array waveguide region being covered with a heating electrode.
3. The multi-channel wavelength division multiplexing 90-degree optical mixing chip of claim 2, wherein the input coupler comprises an input channel TAPER, a free transmission flat plate area FPR and 43 array waveguides TAPER, wherein the FPR consists of a Rowland circle and a part of grating circle, the radius of the grating circle is 222.46 microns, the radius of the Rowland circle is half of that of the grating circle, the input channel TAPER is positioned on one side of the Rowland circle, the 43 array waveguides TAPER are distributed on the circumference of the grating circle at equal intervals, the extension line of the 43 array waveguides TAPER is intersected at a central input channel, namely the center of the grating circle, and the 43 array waveguides TAPER are connected with the array waveguides, and the array waveguides are multimode waveguides with the width of 2 microns.
4. The multi-channel wavelength division multiplexing 90-degree optical mixing chip of claim 3, wherein the output coupler comprises 43 paths of array waveguides TAPER, a free transmission flat plate area FPR and 8 paths of output channels TAPER, wherein the FPR consists of a Roland circle and a part of grating circle, the radius of the Roland circle is half that of the grating circle, the 43 paths of array waveguides TAPER are distributed on one side of the grating circle at equal intervals, the extension lines of the 43 paths of array waveguides TAPER are intersected at the center of the center output channel, namely, the center of the grating circle, the 43 paths of array waveguides TAPER are connected with the array waveguides, and the array waveguides are designed into multimode waveguides with the width of 2 microns.
5. The multi-channel wavelength division multiplexing 90-degree optical mixing chip of claim 4, wherein the heating electrode is formed by connecting two electrodes which are arranged in a serpentine shape and share a cathode in parallel, so that the heating effect is ensured, and meanwhile, the voltage required by heating is reduced.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202411219291.3A CN118837997B (en) | 2024-09-02 | 2024-09-02 | A multi-channel silicon-based wavelength division multiplexing 90-degree optical mixing chip |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202411219291.3A CN118837997B (en) | 2024-09-02 | 2024-09-02 | A multi-channel silicon-based wavelength division multiplexing 90-degree optical mixing chip |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN118837997A CN118837997A (en) | 2024-10-25 |
| CN118837997B true CN118837997B (en) | 2025-06-20 |
Family
ID=93141129
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202411219291.3A Active CN118837997B (en) | 2024-09-02 | 2024-09-02 | A multi-channel silicon-based wavelength division multiplexing 90-degree optical mixing chip |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN118837997B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN119596452B (en) * | 2024-12-30 | 2025-09-02 | 华中光电技术研究所(中国船舶集团有限公司第七一七研究所) | A Silicon-on-Insulator Arrayed Waveguide Grating Chip for Dense Wavelength Division Multiplexing |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104407415A (en) * | 2014-12-09 | 2015-03-11 | 浙江大学 | Switchable polarizer based on MZI (Mach Zehnder Interferometer) silicon substrate |
| CN109991700A (en) * | 2019-03-26 | 2019-07-09 | 昆明理工大学 | A kind of arrayed waveguide grating multiplexer that micro-loop is integrated |
| CN118259514A (en) * | 2024-03-28 | 2024-06-28 | 东南大学 | A phase-compensated silicon-based star-shaped 90-degree optical mixer |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP6286457B2 (en) * | 2016-02-09 | 2018-02-28 | 沖電気工業株式会社 | Optical multiplexing / demultiplexing device and arrayed waveguide diffraction grating type optical wavelength filter |
| CN105759357B (en) * | 2016-05-13 | 2019-09-03 | 东南大学 | A Compact Analog-to-Digital Converter Based on Slot Waveguide |
| CN114726447A (en) * | 2020-12-22 | 2022-07-08 | 上海新微技术研发中心有限公司 | 90-degree optical mixer based on silicon-based silicon nitride waveguide |
| CN115220148A (en) * | 2021-04-15 | 2022-10-21 | 华为技术有限公司 | Array waveguide grating |
| CN114609723A (en) * | 2022-02-25 | 2022-06-10 | 浙江大学 | Light modulator without complex phase correction |
| CN114690313A (en) * | 2022-04-25 | 2022-07-01 | 东南大学 | A compact multimode interference coupler with low insertion loss and large bandwidth based on thick Si3N4 material |
-
2024
- 2024-09-02 CN CN202411219291.3A patent/CN118837997B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104407415A (en) * | 2014-12-09 | 2015-03-11 | 浙江大学 | Switchable polarizer based on MZI (Mach Zehnder Interferometer) silicon substrate |
| CN109991700A (en) * | 2019-03-26 | 2019-07-09 | 昆明理工大学 | A kind of arrayed waveguide grating multiplexer that micro-loop is integrated |
| CN118259514A (en) * | 2024-03-28 | 2024-06-28 | 东南大学 | A phase-compensated silicon-based star-shaped 90-degree optical mixer |
Also Published As
| Publication number | Publication date |
|---|---|
| CN118837997A (en) | 2024-10-25 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US10050717B2 (en) | Multi-stage interferometer circuit with waveform shaping function | |
| US8526102B2 (en) | PLC-type demodulator and optical transmission system | |
| US8588565B2 (en) | Coherent optical detector having a multifunctional waveguide grating | |
| CN101895495B (en) | Method and system for transmitting and receiving by orthogonally dual-polarized differential quaternary phase shift keying | |
| JP4934566B2 (en) | Delay demodulation device | |
| US7978401B2 (en) | Delay demodulation devices | |
| CN102224690A (en) | Frequency offset polarization multiplexing modulation format and system incorporating the same | |
| CN118837997B (en) | A multi-channel silicon-based wavelength division multiplexing 90-degree optical mixing chip | |
| TW202318051A (en) | On-chip integrated wavelength division multiplexer and chip | |
| CN113783653A (en) | Wavelength division multiplexing optical receiver system based on micro-ring resonator | |
| US8477409B2 (en) | PLC-type delay demodulation circuit and PLC-type optical interferometer | |
| CN101980460A (en) | Monolithically integrated multi-wavelength differential quadrature phase shift keying (DQPSK) demodulator and manufacturing method thereof | |
| Stern et al. | Silicon photonic direct-detection phase retrieval receiver | |
| US20080199189A1 (en) | Colorless optical demodulator for differential quadrature phase shift keying dwdm systems | |
| Goh et al. | Novel flexible-format optical modulator with selectable combinations of carrier numbers and modulation levels based on silica-PLC and LiNbO3 hybrid integration | |
| WO2020196216A1 (en) | Polarization multiplexed light transmission/reception circuit | |
| Huang et al. | On-chip mode-division multiplexing transmission with modal crosstalk mitigation employing low-coherence matched detection | |
| CN107070835B (en) | A two-way photon radio frequency OFDM system with phase self-locking and self-coherent detection and its signal processing implementation method | |
| Alkhalifah et al. | Investigation and demonstration of 5G signal transmission over fiber/FSO/wireless links | |
| Shieh et al. | Advanced direct detection schemes | |
| WO2013059244A1 (en) | Compact tunable optical ofdm source | |
| Tamrakar et al. | Performance investigation of bit error rate using mostly utilized modulation schemes in RoF system for the Next Generation Networks | |
| JP5394992B2 (en) | Optical receiver for differential phase modulation signal | |
| CN117459150A (en) | Microwave photon channelized receiving device supporting high-speed sub-channel exchange | |
| Wang et al. | Beyond 1.6-Tb/s Silicon LAN-WDM Transmitter for High-Energy-Efficiency Transmission |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |