A discrete dispersion compensating device based on a multi-channel parallel micro-ring assembly

Abstract

The application discloses a kind of discrete dispersion compensation devices based on multi-channel micro-ring.The upstream waveguide and the downstream waveguide are arranged in parallel and are spaced apart, there are multi-channel parallel micro-ring components between the upstream waveguide and the downstream waveguide, including n micro-rings arranged in the direction of waveguide, there is a delay line on the upstream waveguide between the adjacent two micro-rings, so that different micro-rings adapt different wavelength optical signals;The dispersion compensation signal to be input into the upstream waveguide, is coupled and transmitted into the downstream waveguide through each micro-ring in the multi-channel parallel micro-ring component, is divided into n discrete wavelength signals through n micro-rings, and finally is output after being combined by wavelength division multiplexing in the downstream waveguide.The application combines micro-ring wavelength division multiplexing device and compact delay line, forms on-chip discrete dispersion compensation device, realizes multi-channel, large time delay and low time delay jitter high-performance integrated on-chip dispersion compensation device, can reduce the influence of dispersion on communication system, reduce spectral broadening and distortion, reduce the bit error rate of transmission signal.

Description

Technical Field

[0001] This invention relates to a discrete dispersion compensation device in the field of communications, and more particularly to a discrete dispersion compensation device based on a multi-channel parallel micro-ring component. Background Technology

[0002] In communication systems, long-distance transmission is always accompanied by dispersion effects, leading to pulse broadening and distortion, thus introducing significant crosstalk to the signal. As dispersion accumulates, the system's bit error rate increases rapidly, resulting in a decrease in bandwidth and transmission rate. This delay and phase distortion severely impacts signal synchronization, wavelength division multiplexing (WDM), and long-distance transmission. Dispersion compensation devices can provide accurate delay compensation for optical signals, ensuring stable signal transmission rates and low bit error rates, thereby improving system reliability.

[0003] Currently, commercially available dispersion compensation devices mainly consist of dispersive Bragg fiber gratings (DCFs). These spatial optical devices have a large area, which diminishes their advantages in the rapid development of highly integrated systems, necessitating the replacement with smaller devices. Silicon-based optoelectronic integration technology, compatible with CMOS standard processes, is gradually becoming a major research direction in communication systems. Silicon's high refractive index allows light to be confined to smaller chip structures, enabling highly integrated optical communication systems. On-chip chirped Bragg gratings have become a common design for dispersion compensation; however, because their delay spectrum is highly sensitive to periodic processing tolerances, the resulting group delay ripples are difficult to eliminate, posing a significant obstacle in practical system applications. Summary of the Invention

[0004] In view of the problems existing in the background technology, the present invention provides a discrete dispersion compensation device based on a multi-channel parallel micro-ring component. The dispersion compensation system using a combination of wavelength division multiplexing device and delay line can overcome the group delay ripple problem in principle and provide accurate delay compensation value. It has good practical value in on-chip dispersion compensation devices.

[0005] The technical solution adopted in this invention is:

[0006] This invention includes an uplink waveguide, a multi-channel parallel microring assembly, delay lines, and a downlink waveguide. The uplink and downlink waveguides are arranged in parallel and spaced apart. A multi-channel parallel microring assembly is provided between the uplink and downlink waveguides. The multi-channel parallel microring assembly is mainly composed of n microrings with the same structure but uniformly increasing or decreasing radii, arranged at intervals in the uplink / downlink direction. Different radii correspond to different wavelength channels. A delay line is provided on the uplink waveguide between each pair of adjacent microrings, so that the optical signal passing through the uplink waveguide is delayed by the delay line. n-1 delay lines are provided between the n microring assemblies, so that different microrings can adapt to optical signals of different wavelengths.

[0007] The dispersion compensation signal is input to the uplink waveguide, coupled and transmitted to the downlink waveguide through each microring in the multi-channel parallel microring assembly. This results in the signal to be compensated being divided into n discrete wavelength signals by n microrings in the multi-channel parallel microring assembly. The n discrete wavelength signals are then combined by wavelength division multiplexing in the downlink waveguide and output, thus achieving discrete separation of the input and output signals.

[0008] The n discrete wavelength signals are λ1, λ2, λ3...λ i , λ i+1 ……λ n And i∈[1,n], where i represents the channel number, λ i Let λ represent the i-th discrete wavelength signal. i+1 This represents the (i+1)th discrete wavelength signal. The wavelength difference Δλ between any two adjacent discrete wavelength signals is equal. The wavelength of the discrete wavelength signal increases or decreases sequentially with the channel number by an equal difference.

[0009] The wavelength difference Δλ is specifically determined by the following formula:

[0010] Δλ=λ i+1 -λ i

[0011] When the wavelength difference Δλ is positive, λ i+1 >λ i The wavelength of the discrete wavelength signal increases incrementally with the channel number, and the radius of the micro-ring also increases incrementally with the channel number; when the wavelength difference Δλ is negative, λ i+1 <λ i The wavelength of the discrete wavelength signal decreases by an equal increment with the channel number, and the radius of the micro-ring also decreases by an equal increment with the channel number.

[0012] The delay lines are used to generate a time delay for discrete wavelength signals, and all n-1 delay lines generate the same time delay t0. No time delay is generated for the first discrete wavelength signal λ1, and for each of the remaining discrete wavelength signals λ... i Each signal generates its own time delay through its own number of delay lines, and the i-th discrete wavelength signal λ i The time delay accumulated through i-1 delay lines is t. i = t0*(i-1), and i∈[2,n], that is, the second discrete wavelength signal λ2 passes through one delay line, and the third discrete wavelength signal λ2 passes through two delay lines.

[0013] The dispersion compensation value of the compensation device is specifically determined by the following formula:

[0014] D=t0 / Δλ

[0015] Where D represents the dispersion compensation value, t0 represents that each individual delay line produces the same time delay, and Δλ represents the wavelength difference between each two adjacent discrete wavelength signals.

[0016] Based on the value of the wavelength difference, the following judgment is made: when the wavelength difference Δλ is positive, positive dispersion compensation is achieved, and the dispersion compensation value D>0; when the wavelength difference Δλ is negative, negative dispersion compensation is achieved, and the dispersion compensation value D<0.

[0017] The total compensation bandwidth of the compensation device is (n-1)*Δλ.

[0018] The delay line employs a helical, compact waveguide structure to reduce the area of ​​the compensation device.

[0019] The uplink waveguide, multi-channel parallel microring assembly, delay line, and download waveguide are all monolithically integrated and placed on a silicon substrate, and all of them are made of silicon material.

[0020] This invention utilizes the dense wavelength division multiplexing (WDM) effect of parallel microrings to divide the signal to be compensated into multiple discrete, equally spaced individual wavelength channels. A time-delay line with a fixed delay is added to the connecting waveguide between the parallel microrings. The cumulative delay of different wavelength channels increases with the number of wavelength channels. These delays are then multiplexed into the same waveguide through the download port of the microrings for beam combining. At this point, different wavelengths produce different delays, resulting in a discrete dispersion compensation effect.

[0021] This invention utilizes the wavelength division multiplexing (WDM) function of a multi-channel parallel micro-ring assembly to separate the signal to be compensated into discrete wavelength signals with equal intervals according to wavelength. Delay lines are added between the parallel micro-rings, thereby giving the discrete wavelength signals different delay differences and producing a dispersion compensation effect.

[0022] This invention utilizes the wave decomposition and multiplexing function of a multi-channel parallel micro-ring component to combine the compensated delay lines into the same download waveguide, thereby achieving both multiplexing and input / output separation.

[0023] The beneficial effects of this invention are:

[0024] This invention combines a micro-ring wavelength division multiplexing device and a compact delay line to form an on-chip discrete dispersion compensation device, realizing a high-performance integrated on-chip dispersion compensation device with multiple channels, large delay and low delay jitter. It can reduce the impact of dispersion on the communication system, reduce spectrum broadening and distortion, and reduce the bit error rate of the transmitted signal.

[0025] This invention utilizes the wavelength division multiplexing (WDM) function of parallel micro-ring devices combined with delay lines to divide the signal to be compensated into discrete wavelength signals for compensation. Then, the WDM signals are combined and bundled into the download waveguide through wavelength division multiplexing, thereby achieving input and output signal bundling and separation. This discrete compensation method effectively improves the accuracy of time delay compensation and reduces the impact of time delay fluctuations, and has high practical value in practical applications.

[0026] This invention has the advantages of high integration and low loss of on-chip optical devices, while achieving dispersion compensation performance with multiple channels, large delay and low delay jitter. It can realize high-performance integrated dispersion compensation devices with multiple channels, large delay and low delay jitter on integrated silicon chips, and is suitable for transceiver modules in long-distance transmission communication systems. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the discrete dispersion compensation device based on a multi-channel parallel micro-ring component according to the present invention.

[0028] Figure 2 This is a schematic diagram of the spiral compact waveguide delay line of the present invention.

[0029] Figure 3 These are simulated spectra of each discrete wavelength channel of the micro-ring wavelength division multiplexing device in this embodiment of the invention.

[0030] In the diagram: Upload (1), Parallel micro-ring (2), Delay line (3), and Download waveguide (4). Detailed Implementation

[0031] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0032] like Figure 1 As shown, the discrete dispersion compensation device based on a multi-channel parallel microring assembly includes an uplink waveguide 1 for inputting the signal to be compensated into the device; a parallel microring 2 for wavelength division multiplexing; a delay line 3 for generating time delay between the parallel microrings; and a downlink waveguide 4 for combining the microring downlink signals into the same waveguide.

[0033] Upload waveguide 1 and download waveguide 4 are arranged in parallel and spaced apart. A multi-channel parallel micro-ring assembly 2 is set between the upload waveguide 1 and the download waveguide 4. The multi-channel parallel micro-ring assembly 2 is mainly composed of n micro-rings with the same structure but uniformly increasing or decreasing radius, which are arranged at intervals in the direction of upload waveguide 1 / download waveguide 4. A delay line 3 is set on the upload waveguide 1 between each two adjacent micro-rings, so that the optical signal passing through the upload waveguide 1 is delayed by the delay line 3. n-1 delay lines 3 are set between the n micro-ring assemblies, so that different micro-rings can adapt to optical signals of different wavelengths.

[0034] The dispersion compensation signal is input to the uplink waveguide 1, and is coupled and transmitted to the downlink waveguide 4 through each microring in the multi-channel parallel microring assembly 2. This allows the signal to be compensated to be divided into n discrete wavelength signals through n microrings in the multi-channel parallel microring assembly 2. The n discrete wavelength signals are then output after being combined by wavelength division multiplexing in the downlink waveguide 4, thus achieving discrete separation of the input and output signals.

[0035] A wavelength division multiplexing (WDM) device is connected in parallel with microrings 2. These n microrings divide the compensated signal input through the uplink waveguide into n discrete wavelength signals λ1, λ2, λ3...λ. i , λ i+1 ……λ n The interval between adjacent wavelengths is Δλ = λ i+1 -λ i λ is a constant and can be either positive or negative. When λ is positive... i+1 >λ i When the wavelength increases uniformly with the channel number, the radius of the micro-ring also increases uniformly with the channel number; when λ is negative... i+1 <λ i The wavelength decreases uniformly with the channel number, and the radius of the micro-ring also decreases uniformly with the channel number. The total compensation bandwidth is (n-1)*Δλ. The discrete wavelength signals downloaded by the parallel micro-ring 2 are all multiplexed and bundled into the download waveguide 4 through the wave decomposition of the parallel micro-ring 2, realizing the separation of input and output signals.

[0036] Delay line 3 is used to generate a time delay for discrete wavelength signals, and all n-1 delay lines 3 generate the same time delay t0. No time delay is generated for the first discrete wavelength signal λ1, and for each of the remaining discrete wavelength signals λ... i Each signal generates its own time delay through its own number of delay lines, and the i-th discrete wavelength signal λ i The time delay accumulated through i-1 delay lines is t. i = t0*(i-1), and i∈[2,n], that is, the second discrete wavelength signal λ2 passes through one delay line, and the third discrete wavelength signal λ2 passes through two delay lines. Positive dispersion compensation is achieved when Δλ is positive, and D>0; negative dispersion compensation is achieved when Δλ is negative, and D<0.

[0037] like Figure 2 As shown, in the specific implementation, the delay line 3 adopts a spiral compact waveguide structure to reduce the device area. The uplink waveguide, parallel microring, delay line, and downlink waveguide are all placed on the silicon substrate and fabricated using monolithic integration. The core layer material is also silicon.

[0038] Examples of the invention are as follows:

[0039] This example uses silicon-based optical waveguides, wavelength division multiplexing (WDM) devices, and delay lines based on silicon-insulator (SOI) material. The core layer is silicon, 220 nm thick, with a refractive index of 3.4744, operating in the communication band around 1550 nm. The upper cladding is silicon dioxide. A 450 nm wide single-mode waveguide is selected as the input / output waveguide, the multiplexing channel waveguides for each wavelength, and the connecting waveguide.

[0040] like Figure 1 As shown, the wavelength division multiplexing (WDM) device in this example uses a combination of multiple first-order microrings. First-order microrings have a large fabrication tolerance. In actual device design, the radius and coupling region width of each microring are controlled to match the wavelength channels with corresponding precision, thereby performing WDM multiplexing on the optical signal within the required compensation bandwidth and processing it into discrete wavelength signals. The download wavelength is changed by fine-tuning the radius of each cascaded ring, achieving the download function of multiple adjacent single-wavelength channels with equal spacing. The wavelength channels corresponding to each microring may experience wavelength drift due to fabrication errors, but the precision will not change significantly. Precision, i.e., the wavelength spacing between adjacent wavelength channels, can be fine-tuned by placing heating electrodes on the microrings. Adjusting the voltage across the heating electrodes generates different temperatures, and wavelength alignment is achieved through the refractive index change caused by the thermo-optical effect.

[0041] This example design uses a total dispersion compensation bandwidth of n*Δλ = 30 nm, with a wavelength range of 1530–1560 nm. A parallel microring divides the wavelengths within this bandwidth into n = 16 discrete wavelength channels, with an adjacent wavelength interval of Δλ = 2 nm. The simulated spectra of each discrete wavelength channel of the microring wavelength division multiplexing device are shown below. Figure 3 As shown. The designed delay unit duration t0 = 20 ps, ​​and the delay line is as follows. Figure 2 The diagram shows a helical compact waveguide structure. The dispersion compensation value of the device is D = t0 / Δλ = 10 ps / nm.

[0042] As can be seen from this embodiment, the present invention utilizes a discrete dispersion compensation device composed of a multi-channel parallel micro-ring component and a compact delay line to divide the signal to be compensated into discrete wavelength signals for compensation. These signals are then beamed together through wavelet demultiplexing and back-bearing into a download waveguide, achieving input and output signal beaming and separation. This discrete compensation method effectively improves the accuracy of time delay compensation and reduces the impact of time delay fluctuations, demonstrating high practical value in real-world applications.

[0043] The above embodiments are used to explain and illustrate the present invention, but not to limit the present invention. Any modifications and changes made to the present invention within the spirit and scope of the claims shall fall within the protection scope of the present invention.

Claims

1. A discrete dispersion compensation device based on a multi-channel parallel micro-ring assembly, characterized in that: The system includes an uplink waveguide (1), a multi-channel parallel microring assembly (2), a delay line (3), and a downlink waveguide (4). The uplink waveguide (1) and the downlink waveguide (4) are arranged in parallel and spaced apart. A multi-channel parallel microring assembly (2) is provided between the uplink waveguide (1) and the downlink waveguide (4). The multi-channel parallel microring assembly (2) is composed of n microrings with the same structure but uniformly increasing or decreasing radii, arranged at intervals in the direction of the uplink waveguide (1) / the downlink waveguide (4). A delay line (3) is provided on the uplink waveguide (1) between each two adjacent microrings, so that different microrings can be adapted to optical signals of different wavelengths. The dispersion compensation signal is input into the uplink waveguide (1), coupled and transmitted to the downlink waveguide (4) through each microring in the multi-channel parallel microring assembly (2). The dispersion compensation signal is divided into n discrete wavelength signals through the n microrings in the multi-channel parallel microring assembly (2). The n discrete wavelength signals are output after being combined by wavelength division multiplexing in the downlink waveguide (4). The n discrete wavelength signals are λ1, λ2, λ3...λ i , λ i+1 ……λ n And i∈[1,n], where i represents the channel number, λ i Let λ represent the i-th discrete wavelength signal. i+1 This represents the (i+1)th discrete wavelength signal. The wavelength difference Δλ between any two adjacent discrete wavelength signals is equal. The wavelength of the discrete wavelength signal increases or decreases by an equal difference as the channel number increases. The delay line (3) is used to generate a time delay for discrete wavelength signals, and all delay lines (3) generate the same time delay t0. No time delay is generated for the first discrete wavelength signal λ1, and for each of the remaining discrete wavelength signals λ... i Each signal generates its own time delay through its own number of delay lines, and the i-th discrete wavelength signal λ i The time delay accumulated through i-1 delay lines is t. i =t0*(i-1), and i∈[2,n].

2. The discrete dispersion compensation device based on a multi-channel parallel micro-ring assembly according to claim 1, characterized in that: The dispersion compensation value of the compensation device is specifically determined by the following formula: D=t0 / Δλ Where D represents the dispersion compensation value, t0 represents that each delay line (3) produces the same time delay, and Δλ represents the wavelength difference between each two adjacent discrete wavelength signals.

3. The discrete dispersion compensation device based on a multi-channel parallel micro-ring assembly according to claim 1, characterized in that: The total compensation bandwidth of the compensation device is (n-1)*Δλ.

4. A discrete dispersion compensation device based on a multi-channel parallel micro-ring assembly according to claim 1, characterized in that: The delay line (3) adopts a helical compact waveguide structure.

5. A discrete dispersion compensation device based on a multi-channel parallel micro-ring assembly according to claim 1, characterized in that: The uplink waveguide (1), the multi-channel parallel micro-ring assembly (2), the delay line (3), and the download waveguide (4) are all monolithically integrated and placed on a silicon substrate, and the uplink waveguide (1), the multi-channel parallel micro-ring assembly (2), the delay line (3), and the download waveguide (4) are all made of silicon material.

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