Controllable capacity scalable optical communication device

Abstract

The application provides a controllable capacity scalable optical communication device, which comprises a cascaded Mach-Zehnder interferometer optical switch, a parallel modulator array, an on-chip optical interface array and an optical fiber array connected in sequence; the cascaded Mach-Zehnder interferometer optical switch is composed of a plurality of Mach-Zehnder interferometer optical switches with the same structure, and optical signals input into the cascaded Mach-Zehnder interferometer optical switch are branched into a plurality of independent optical signals; the plurality of optical signals are input into the parallel modulator array for modulation, and then input into the on-chip optical interface array and coupled to the optical fiber array for transmission. The application can realize low-power consumption control of channel selection, channel number and channel rate, and obtain a dynamic capacity scalable photonic integrated interconnection by using the cascaded Mach-Zehnder interferometer optical switch in the optical communication system; meanwhile, the phase modulation efficiency of the Mach-Zehnder interferometer arm is improved by using a mode conversion structure, the control voltage required for capacity scaling is reduced, and thus the power consumption is reduced.

Description

Technical Field

[0001] This invention relates to the field of optical communication and co-packaged photonic integrated interconnection, specifically to an optical communication device with controllable capacity scaling. Background Technology

[0002] With the proliferation of mobile devices, high-definition video, and global cloud services, network data traffic has steadily increased over the past decade, creating a substantial and rapidly growing market for optical links used within or between data centers. Currently, these optical links are primarily based on Ethernet and deployed in the form of pluggable optical modules. However, with the doubling of data center network traffic, the high-loss electrical links between the switch chip and the front-panel optical modules have resulted in significant power consumption and cost. Furthermore, the space on the front panel of the switch is no longer sufficient to accommodate a large number of traditional pluggable optical modules. This has prompted optical modules to be placed closer to the switch chip and ultimately co-packaged with the switch chip, achieving co-packaged optics (CPO).

[0003] While statistical calculations show that co-packaged optical modules can save 25% to 50% in power consumption and cost compared to pluggable optical modules, this comes at the cost of the flexible deployment advantage of pluggable modules. Pluggable modules offer field accessibility and ease of replacement to accommodate changes in the capacity of data center network nodes, allowing for easy control of input / output capacity scaling and meeting real-time dynamic adjustments to network traffic. CPOs, being co-packaged with the switch chip, are less convenient for adjustment and replacement. Therefore, there is an urgent need to propose an optical communication system at the photonic integrated chip level that enables capacity scaling control. This system should not only meet the needs of dynamic traffic adjustments in data center nodes for CPO capacity scaling control but also allow for the matching of different capacity optical module packaging standards using the same photonic integrated interconnect system, facilitating wafer-level mass production and reducing costs.

[0004] In addition, to meet the low power consumption requirements of the next generation of high-capacity switches for CPO, the additional voltage introduced to control capacity scaling should be minimized to achieve low power control of optical module channel selection, number of channels and channel rate. Summary of the Invention

[0005] In view of the deficiencies in the prior art, the purpose of this invention is to provide an optical communication device with controllable capacity scaling.

[0006] According to the present invention, a controllable capacity scaling optical communication device includes a cascaded Mach-Zehnder interferometer optical switch, a parallel modulator array, an on-chip optical interface array, and an optical fiber array connected in sequence. The cascaded Mach-Zehnder interferometer optical switch is composed of multiple Mach-Zehnder interferometer optical switches with identical structures cascaded together. An optical signal input to the cascaded Mach-Zehnder interferometer optical switch is split into multiple independent optical signals. The multiple optical signals are respectively input to the parallel modulator array for modulation, and then input to the on-chip optical interface array and coupled to the optical fiber array for transmission.

[0007] Preferably, the cascaded Mach-Zehnder interferometer optical switch comprises three cascaded layers: a first Mach-Zehnder interferometer optical switch, a second and a third Mach-Zehnder interferometer optical switch, and a fourth, fifth, sixth, and seventh Mach-Zehnder interferometer optical switch. The output terminal of the first Mach-Zehnder interferometer optical switch is connected to the input terminals of the second and third Mach-Zehnder interferometer optical switches, respectively. The output terminal of the second Mach-Zehnder interferometer optical switch is connected to the input terminals of the fourth and fifth Mach-Zehnder interferometer optical switches, respectively. The output terminal of the third Mach-Zehnder interferometer optical switch is connected to the input terminals of the sixth and seventh Mach-Zehnder interferometer optical switches, respectively.

[0008] Preferably, the Mach-Zehnder interferometer optical switch includes: an input waveguide, an output waveguide, a 1*2 multimode interference coupler, a 2*2 multimode interference coupler, an upper arm phase modulation region, a lower arm phase modulation region, a first return loop waveguide, a second return loop waveguide, a third return loop waveguide, a fourth return loop waveguide, and eight identical mode converters. The mode converters are used to convert the optical signals input to them into optical signals of different order modes and output them. The mode converters are respectively the first mode converter, the second mode converter, the third mode converter, the fourth mode converter, the fifth mode converter, the sixth mode converter, the seventh mode converter, and the eighth mode converter.

[0009] Preferably, the input waveguide is used to receive the initial first optical signal, and the output end of the input waveguide is connected to the input end of the 1*2 multimode interference coupler. The 1*2 multimode interference coupler is used to equally split the initial first optical signal to form a second optical signal and a third optical signal. The output end of the 1*2 multimode interference coupler is connected to the upper arm phase modulation region and the lower arm phase modulation region, respectively. The upper arm phase modulation region and the lower arm phase modulation region are used to perform phase modulation on the transmitted optical signal. The output ends of the upper arm phase modulation region and the lower arm phase modulation region are both connected to the input end of the 2*2 multimode interference coupler, and the output end of the 2*2 multimode interference coupler is connected to the output waveguide.

[0010] Preferably, the two ends of the first return loop waveguide are respectively connected to the output end of the upper arm phase modulation zone and the input end of the first mode converter, and the first mode converter is used to convert the second optical signal and output it as a fourth optical signal.

[0011] Preferably, the third mode converter is used to convert the fourth optical signal and output it as a sixth optical signal. The two ends of the third return loop waveguide are respectively connected to the output end of the third mode converter and the input end of the fourth mode converter. The fourth mode converter is used to convert the sixth optical signal and output it as a seventh optical signal. The seventh mode converter is used to convert the seventh optical signal and output it as a tenth optical signal.

[0012] Preferably, the two ends of the second return loop waveguide are respectively connected to the output end of the lower arm phase modulation zone and the input end of the second mode converter, and the second mode converter is used to convert the third optical signal and output it as a fifth optical signal.

[0013] Preferably, the fifth mode converter is used to convert the fifth optical signal and output it as an eighth optical signal. The two ends of the fourth return loop waveguide are respectively connected to the output end of the fifth mode converter and the input end of the sixth mode converter. The sixth mode converter is used to convert the eighth optical signal and output it as a ninth optical signal. The eighth mode converter is used to convert the ninth optical signal and output it as an eleventh optical signal. The input ends of the 2*2 multimode interference coupler are respectively input to the tenth optical signal and the eleventh optical signal.

[0014] Preferably, the cascaded Mach-Zehnder interferometer optical switch can achieve 2 n The state switching of the road light signal, where n is an integer.

[0015] Preferably, the upper arm phase modulation region and the lower arm phase modulation region have the same structure, both including a silicon-based electro-optic phase modulation region based on ion doping, a silicon-based thermo-optic phase modulation region, a silicon-based germanium ion-doped phase modulation region, or a silicon-based deposited phase change material phase modulation region.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1. This invention enables low-power control of channel selection, number of channels, and channel rate through a cascaded Mach-Zehnder interferometer optical switch and a parallel modulation array structure in an optical communication system, resulting in a photonic integrated interconnect with dynamic capacity scaling. Simultaneously, by utilizing a mode conversion structure, the phase modulation efficiency of the Mach-Zehnder interferometer arms is improved, reducing the control voltage required for capacity scaling and thus lowering power consumption.

[0018] 2. This invention enables the selection and switching of eight optical paths by driving a three-stage cascaded Mach-Zehnder interferometer optical switch with different control voltages. This allows for switching between one, two, four, and eight working optical paths. Further cascading can expand to 16, 32, 64, and more optical paths, allowing for channel selection and control. The corresponding working optical path signal is modulated by a modulator and then coupled to an optical fiber for transmission via an on-chip optical interface. This achieves dynamic capacity scaling of photonic integrated interconnection, matching different capacity optical module packaging standards, and meeting the data center node traffic dynamic adjustment requirements for CPO capacity scaling control.

[0019] 3. This invention uses the upper and lower phase modulation regions of the Mach-Zehnder interferometer switch to perform phase modulation on the transmitted optical signal, causing a phase change. Since different modes of optical signals do not interfere or crosstalk with each other when they are phase modulated by the upper and lower modulation arms of the Mach-Zehnder interferometer, the optical signal passes through the phase modulation region multiple times in different order modes. The phase change amount can be superimposed each time, thereby improving the phase modulation efficiency and reducing the driving voltage required to control the output state of the optical path. According to the phase difference between the two optical signals, the two output terminals will have different output situations, which can realize the output of all light from one output terminal or the output of equal light from both output terminals. Attached Figure Description

[0020] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0021] Figure 1 This is a schematic diagram illustrating the overall structure of the optical communication device with controllable capacity expansion and contraction, which is the main feature of this invention.

[0022] Figure 2 This is a schematic diagram illustrating the structure of the optical switch of the Mach-Zehnder interferometer, which is the main feature of this invention.

[0023] Figure 3 This is a schematic diagram illustrating the silicon-based electro-optic phase modulation region based on L-type ion doping, which is the main feature of this invention.

[0024] Figure 4 This is a schematic diagram illustrating the silicon-based electro-optic phase modulation region based on U-shaped doping, which is the main feature of this invention.

[0025] Figure 5 This is a schematic diagram illustrating the phase modulation region based on the thermo-optic effect, which is the main feature of this invention.

[0026] Figure 6 This is a schematic diagram illustrating the phase-tuning region based on germanium ion doping, which is the main feature of this invention.

[0027] Figure 7 This is a schematic diagram illustrating the phase-tuning region based on phase change materials, which is the main feature of this invention.

[0028] As shown in the figure:

[0029] Cascaded Mach-Zehnder interferometer, optical switch 10000, parallel modulator array 20000

[0030] 30000 on-chip optical interface arrays and 40000 fiber optic arrays

[0031] First Mach-Zehnder interferometer optical switch 11000; Second Mach-Zehnder interferometer optical switch 12000

[0032] The third Mach-Zehnder interferometer optical switch 13000; the fourth Mach-Zehnder interferometer optical switch 14000.

[0033] The fifth Mach-Zehnder interferometer optical switch 15000; the sixth Mach-Zehnder interferometer optical switch 16000.

[0034] The seventh Mach-Zehnder interferometer has an optical switch of 17000 and an input waveguide of 11010.

[0035] 1*2 multimode interference coupler 11020, upper arm phase adjustment zone 11030

[0036] Lower arm phase modulation region 11040, first return loop waveguide 11050

[0037] First mode converter 11060 Second return loop waveguide 11070

[0038] Second-mode converter 11080 Third-mode converter 11090

[0039] Third return loop waveguide 11100 Fourth mode converter 11110

[0040] Fifth mode converter 11120; Fourth return loop waveguide 11130

[0041] Sixth Mode Converter 11140 Seventh Mode Converter 11150

[0042] Eighth mode converter 11160 2*2 multimode interference coupler 11170

[0043] P-type heavily doped region 11031 N-type heavily doped region 11032

[0044] P-type lightly doped region 11033, N-type lightly doped region 11034

[0045] First modulation electrode 11035 Second modulation electrode 11036

[0046] Silica top cladding 11037 Silica bottom cladding 11038

[0047] Silicon substrate 11039 First modulation electrode 110311

[0048] Second modulation electrode 110321, thermal electrode 110331

[0049] 110341 silicon dioxide cladding, 110351 silicon waveguide

[0050] 110361 silicon dioxide undercoat 110371 silicon substrate

[0051] Germanium ion-doped region 110312, silicon ridge waveguide 110322

[0052] First silicon dioxide upper cladding 110332 First silicon dioxide lower cladding 110342

[0053] First silicon substrate 110352, modulation electrode 110313

[0054] Phase change material 110323 deposited on silicon waveguide; silicon waveguide 110333

[0055] Second silicon dioxide undercoat 110343 Second silicon substrate 110353 Detailed Implementation

[0056] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0057] like Figure 1As shown, an optical communication device with controllable capacity expansion according to the present invention includes a cascaded Mach-Zehnder interferometer optical switch 10000, a parallel modulator array 20000, an on-chip optical interface array 30000, and an optical fiber array 40000 connected in sequence. The cascaded Mach-Zehnder interferometer optical switch 10000 is composed of multiple Mach-Zehnder interferometer optical switches with identical structures cascaded together. Optical signals input to the cascaded Mach-Zehnder interferometer optical switch 10000 are split into multiple independent optical signals. These multiple optical signals are respectively input to the parallel modulator array 20000 for modulation, and then input to the on-chip optical interface array 30000 and coupled to the optical fiber array 40000 for transmission. The cascaded Mach-Zehnder interferometer optical switch 10000 is used to realize the selection of working channels and control the number and rate of channels. The parallel modulator array 20000 performs electro-optic modulation on each optical signal output from the cascaded Mach-Zehnder interferometer optical switch 10000. The on-chip optical interface array 30000 is used to couple various modulated optical signals into the transmission optical fiber. The fiber array 40000 transmits the various modulated optical signals.

[0058] This application proposes a controllable capacity-scaling optical communication device, relating to an optical communication system based on a cascaded Mach-Zehnder interferometer optical switch 10000 and a parallel modulation array 20000. This system enables low-power control of channel selection, channel number, and channel rate, achieving dynamically scalable photonic integrated interconnects. Simultaneously, by utilizing a mode-switching structure, the phase modulation efficiency of the Mach-Zehnder interferometer arms is improved, reducing the control voltage required for capacity scaling and thus lowering power consumption.

[0059] The cascaded Mach-Zehnder interferometer optical switch 10000 of this application, taking a three-layer cascade as an example, allows for the selection and switching of eight optical paths and the control of the number of working optical paths (one, two, four, or eight). The corresponding working optical path signal is modulated by a modulator and then coupled to an optical fiber for transmission via an on-chip optical interface, thereby realizing a dynamically scalable co-mounted photonic integrated interconnect system. The first layer consists of the first Mach-Zehnder interferometer optical switch 11000; the second layer consists of the second and third Mach-Zehnder interferometer optical switches 12000 and 13000; and the third layer consists of the fourth, fifth, sixth, and seventh Mach-Zehnder interferometer optical switches 14000, 15000, 16000, and 17000. The output of the first Mach-Zehnder interferometer optical switch 11000 is connected to the second Mach-Zehnder interferometer... The input terminals of optical switch 12000 and optical switch 13000 of the third Mach-Zehnder interferometer are connected; the output terminal of optical switch 12000 of the second Mach-Zehnder interferometer is connected to the input terminals of optical switches 14000 and 15000 of the fourth and fifth Mach-Zehnder interferometers, respectively; the output terminal of optical switch 13000 of the third Mach-Zehnder interferometer is connected to the input terminals of optical switches 16000 and 17000 of the sixth and seventh Mach-Zehnder interferometers, respectively.

[0060] like Figure 2 As shown, the basic structure of the cascaded optical switch in this application is a mode-multiplexed Mach-Zehnder interferometer optical switch, with each optical switch having an identical structure. It can be an electrically tunable / thermally tunable optical switch based on a mode-multiplexed Mach-Zehnder interferometer structure, a germanium-doped non-volatile control optical switch based on the same structure, or a phase-change material non-volatile control optical switch based on the same structure. Taking the 11000 as an example, the Mach-Zehnder interferometer optical switch includes: an input waveguide 11010, an output waveguide, a 1*2 multimode interference coupler 11020, a 2*2 multimode interference coupler 11170, an upper arm phase modulation region 11030, a lower arm phase modulation region 11040, a first return loop waveguide 11050, a second return loop waveguide 11070, a third return loop waveguide 11100, a fourth return loop waveguide 11130, and eight identical mode converters. The mode converters are used to convert the optical signals input to them into optical signals of different order modes and output them. The mode converters are the first mode converter 11060, the second mode converter 11080, the third mode converter 11090, the fourth mode converter 11110, the fifth mode converter 11120, the sixth mode converter 11140, the seventh mode converter 11150, and the eighth mode converter 11160.

[0061] The upper arm phase modulation region 11030 and lower arm phase modulation region 11040 of the Mach-Zehnder interferometer switch modulate the phase of the transmitted optical signal, causing a phase change. Since different modes of optical signals do not interfere or crosstalk with each other when undergoing phase modulation through the upper and lower modulation arms of the Mach-Zehnder interferometer, the optical signal passes through the phase modulation region multiple times in different order modes. The phase changes each time can be superimposed, thereby improving phase modulation efficiency and reducing the driving voltage required to control the output state of the optical path. Based on the phase difference between the two optical signals, the two output terminals will have different output states, enabling the output of all light from one output terminal or the output of equal light from both output terminals. Cascading the Mach-Zehnder interferometer optical switch 10000 expands to allow state switching between multiple optical outputs, enabling the selection and quantity control of working optical path channels. The optical signal in the corresponding working optical path is modulated by the parallel modulator array 20000 and then coupled to the fiber array 40000 by the on-chip optical interface array 30000 for transmission, thus realizing a dynamically scalable co-mounted photonic integrated interconnect system.

[0062] The input waveguide 11010 is used to receive the initial first optical signal. The output end of the input waveguide 11010 is connected to the input end of the 1*2 multimode interference coupler 11020. The 1*2 multimode interference coupler 11020 is used to equally split the initial first optical signal to form the second and third optical signals. The output end of the 1*2 multimode interference coupler 11020 is connected to the upper arm phase modulation region 11030 and the lower arm phase modulation region 11040, respectively. The upper arm phase modulation region 11030 and the lower arm phase modulation region 11040 are used to perform phase modulation on the transmitted optical signal. The output ends of the upper arm phase modulation region 11030 and the lower arm phase modulation region 11040 are both connected to the input end of the 2*2 multimode interference coupler 11170. The output end of the 2*2 multimode interference coupler 11170 is connected to the output waveguide.

[0063] The two ends of the first return loop waveguide 11050 are connected to the output end of the upper arm phase modulation area 11030 and the input end of the first mode converter 11060, respectively. The first mode converter 11060 is used to convert the second optical signal and output it as the fourth optical signal. The third mode converter 11090 is used to convert the fourth optical signal and output it as the sixth optical signal. The two ends of the third return loop waveguide 11100 are connected to the output end of the third mode converter 11090 and the input end of the fourth mode converter 11110, respectively. The fourth mode converter 11110 is used to convert the sixth optical signal and output it as the seventh optical signal. The seventh mode converter 11150 is used to convert the seventh optical signal and output it as the tenth optical signal. The two ends of the second return loop waveguide 11070 are connected to the output end of the lower arm phase modulation area 11040 and the input end of the second mode converter 11080, respectively. The second mode converter 11080 is used to convert the third optical signal and output it as the fifth optical signal. The fifth mode converter 11120 converts the fifth optical signal and outputs it as the eighth optical signal. The two ends of the fourth return loop waveguide 11130 are connected to the output of the fifth mode converter 11120 and the input of the sixth mode converter 11140, respectively. The sixth mode converter 11140 converts the eighth optical signal and outputs it as the ninth optical signal, and the eighth mode converter 11160 converts the ninth optical signal and outputs it as the eleventh optical signal. The inputs of the 2*2 multimode interference coupler 11170 are the tenth and eleventh optical signals, respectively. Based on the phase difference between the two optical signals, the two outputs will have different output states, allowing control to achieve output from different ports or equal output from both ports. Cascading this structure can expand to multiple optical output states, enabling selection and quantity control of the working optical path channels.

[0064] Input waveguide 11010 receives the initial first optical signal. A 1x2 multimode interference coupler 11020 equally splits the first optical signal into second and third optical signals, which are respectively input to the upper and lower arms of the Mach-Zehnder interferometer. First return loop waveguide 11050 is connected at both ends to the input of the first mode converter and the upper modulation arm, respectively, inputting the second optical signal into the first mode converter. First mode converter 11060 performs mode conversion on the second optical signal and outputs a fourth optical signal. Second return loop waveguide 11070 is connected at both ends to the input of the second mode converter and the lower modulation arm of the Mach-Zehnder interferometer, respectively, inputting the third optical signal into the second mode converter. Second mode converter 11080 performs mode conversion on the third optical signal and outputs a fifth optical signal. Third mode converter 11090 performs mode conversion on the fourth optical signal and outputs a sixth optical signal. The third return loop waveguide 11100 is connected at both ends to the output of the third mode converter and the input of the fourth mode converter, respectively, inputting the sixth optical signal into the fourth mode converter. The fourth mode converter 11110 performs mode conversion on the sixth optical signal and outputs the seventh optical signal. The fifth mode converter 11120 performs mode conversion on the fifth optical signal and outputs the eighth optical signal. The fourth return loop waveguide 11130 is connected at both ends to the output of the fifth mode converter and the input of the sixth mode converter, respectively, inputting the eighth optical signal into the sixth mode converter. The sixth mode converter 11140 performs mode conversion on the eighth optical signal and outputs the ninth optical signal. The seventh mode converter 11150 performs mode conversion on the seventh optical signal and outputs the tenth optical signal. The eighth mode converter 11160 performs mode conversion on the ninth optical signal and outputs the eleventh optical signal. The Mach-Zehnder interferometer's upper arm phase modulation region 11030 and lower arm phase modulation region 11040 modulate the phase of the transmitted optical signal, causing a phase change. The 2x2 multimode interference coupler 11170 receives the tenth and eleventh optical signals at its inputs. Depending on the phase difference between the two optical signals, the two outputs will have different output configurations, allowing for either outputting all light from one output or outputting equal amounts of light from both outputs.

[0065] Among them, the first, second, third, sixth, eighth, tenth, and eleventh optical signals are the first-mode optical signals; the fourth and fifth optical signals are the second-mode optical signals; and the seventh and ninth optical signals are the third-mode optical signals. It should be noted that the first, second, and third modes can be any optical waveguide transmission mode. The following explanation uses TE0 as the first mode, TE1 as the second mode, and TE2 as the third mode as an example.

[0066] The first through eighth mode converters all have the same structure, and their common function is to convert the input optical signal into optical signals of different orders and output them. Since the optical signals of different orders do not interfere or crosstalk with each other when they are phase modulated by the upper and lower modulation arms of the Mach-Zehnder interferometer, the optical signal passes through the phase modulation region multiple times in different orders of modes. The phase change amount of each time can be superimposed, thereby improving the phase modulation efficiency and reducing the driving voltage required to control the output state of the optical path.

[0067] like Figure 3 and 4 As shown, the upper arm phase modulation region 11030 and the lower arm phase modulation region 11040 of the Mach-Zehnder interferometer have the same structure. They can be silicon-based electro-optic phase modulation regions, silicon-based thermo-optic phase modulation regions, silicon-based germanium ion-doped phase modulation regions, or silicon-based deposited phase change material phase modulation regions based on ion doping. Figure 3 This is a silicon-based electro-optic phase modulation region based on L-type ion doping. Figure 4 For example, the phase modulation region 11030 of the upper arm of a Mach-Zehnder interferometer is a silicon-based electro-optic phase modulation region based on U-type doping. Its structure includes: a heavily doped P-type region 11031, a heavily doped N-type region 11032, a lightly doped P-type region 11033, a lightly doped N-type region 11034, a first modulation electrode 11035, a second modulation electrode 11036, an upper silicon dioxide cladding layer 11037, a lower silicon dioxide cladding layer 11038, and a silicon substrate 11039. Specifically, an L-type or U-type carrier depletion junction is formed between the P-type lightly doped region 11033 and the N-type lightly doped region 11034. The modulation signal is applied to the low-resistance P-type heavily doped region 11031 and N-type heavily doped region 11032 through the first electrode 11035 and the second electrode 11036, respectively, thereby adjusting the carrier concentration of the junction formed by the P-type lightly doped region 11033 and the N-type lightly doped region 11034, and thus changing the effective refractive index of the optical signal in the waveguide. Thanks to the lateral distribution of the L-type / U-type carrier depletion junction throughout the silicon waveguide region, effective refractive index / phase modulation can be generated for both the base film optical signal and the higher-order mode optical signal.

[0068] like Figure 5As shown, in some specific embodiments, the phase modulation region 11030 of the upper arm and the phase modulation region 11040 of the Mach-Zehnder interferometer can also be phase modulation regions based on thermo-optical effects. These include: a first modulation electrode 110311, a second modulation electrode 110321, a thermoelectrode 110331, a silicon dioxide upper cladding layer 110341, a silicon waveguide 110351, a silicon dioxide lower cladding layer 110361, and a silicon substrate 110371. Specifically, the modulation electrical signal is applied to the thermoelectrode 110331 through the first modulation electrode 110311 and the second modulation electrode 110321, causing the thermoelectrode to generate a thermal effect, changing its temperature, and thus adjusting the temperature of the lower waveguide, thereby changing the effective refractive index and phase of the optical signal within the waveguide.

[0069] like Figure 6 As shown, in some specific embodiments, the phase modulation region 11030 of the upper arm and the phase modulation region 11040 of the Mach-Zehnder interferometer can also be phase modulation regions based on germanium ion doping. These include: a germanium ion-doped region 110312, a silicon ridge waveguide 110322, a first silicon dioxide upper cladding layer 110332, a first silicon dioxide lower cladding layer 110342, and a first silicon substrate 110352. Specifically, germanium ions are implanted into the silicon waveguide to form a germanium ion-doped region, thereby changing the refractive index of the phase modulation region. After laser annealing, the germanium ion-doped region can be erased, restoring the original refractive index properties of the silicon waveguide. That is, through ion implantation and laser annealing processes, the effective refractive index of the optical signal within the waveguide can also be changed, thereby altering the phase. Compared to silicon-based electro-optic / thermo-optic phase modulation regions, germanium ion doping phase modulation is non-volatile and can maintain phase modulation in this state after doping / annealing without requiring a continuous voltage supply to the electro-optic / thermo-optic phase modulation region. However, the disadvantage is that the injected germanium ions are completely erased after laser annealing, and only a single state selection switch can be performed.

[0070] like Figure 7As shown, in some specific embodiments, the phase modulation region 11030 of the upper arm and the phase modulation region 11040 of the Mach-Zehnder interferometer can also be phase modulation regions based on phase change materials. These include: a modulation electrode 110313, a phase change material 110323 deposited on a silicon waveguide, a silicon waveguide 110333, a second silicon dioxide lower cladding layer 110343, and a second silicon substrate 110353. Specifically, a modulation electrical signal is applied to the phase change material through the modulation electrode 110313, causing a temperature change in the phase change material region, thereby changing its refractive index to alter the effective refractive index and phase of the optical signal within the underlying silicon waveguide. The refractive index change of the phase change material is also non-volatile; that is, after adjusting to a certain refractive index / phase change amount, the modulation voltage can be removed, and the phase change amount in the corresponding state will remain constant. When a state switch is required, the voltage is applied again to change the temperature, causing the refractive index / phase of the phase change material to change to the corresponding state. Unlike germanium ion-doped phase-tuning regions, phase-tuning regions based on phase change materials can undergo multiple reconfigurable non-volatile state switching.

[0071] The following explanation, using TE0 as the first mode optical signal, TE1 as the second mode optical signal, and TE2 as the third mode optical signal, illustrates the specific working principle of this application's embodiment: The optical signal is input to the cascaded Mach-Zehnder interferometer optical switch (taking a three-layer cascade as an example) 10000. Through different control voltage states in the phase modulation zones of each optical switch, the working selection and switching between eight optical paths can be achieved, as well as the switching of the number of working optical paths between one, two, four, and eight paths. The corresponding working optical path signal is modulated by the parallel modulator array 20000 and then coupled to the optical fiber 40000 via the on-chip optical interface 30000 for transmission, thereby realizing a dynamically scalable co-mounted photonic integrated interconnect system.

[0072] To reduce the control voltage required for switching the number of working optical paths, thereby reducing power consumption, a mode-multiplexed Mach-Zehnder interferometer optical switch 11000-17000 is used as the basic structure of the cascaded optical switch array. Taking 11000 as an example, the first optical signal is input in TE0 mode through the input waveguide 11010. After passing through a 1*2 multimode interference coupler 11020, the first optical signal is equally split into second and third optical signals, which are respectively input to the upper and lower arms of the Mach-Zehnder interferometer. The phase modulation areas 11030 of the upper arm and 11040 of the lower arm of the Mach-Zehnder interferometer perform phase modulation on the second and third optical signals, respectively. Then, the second optical signal enters the first mode converter 11060 through the first return loop waveguide 11050 for mode conversion, changing from the original TE0 mode to TE1 mode. The second optical signal is converted into the fourth optical signal after mode conversion. Similarly, the third optical signal enters the second mode converter via the second return loop waveguide 11070, converting from the original TE0 mode to TE1 mode. After mode conversion, the third optical signal becomes the fifth optical signal and is output. The fourth and fifth optical signals output from the first and second mode converters pass through the phase modulation areas 11030 and 11040 of the upper and lower arms of the Mach-Zehnder interferometer, respectively, in opposite directions for phase modulation. After modulation, the fourth optical signal undergoes mode conversion via the third mode converter 11090, converting from the original TE1 mode to TE0 mode and outputting the sixth optical signal. The sixth optical signal then enters the fourth mode converter 11110 via the third return loop waveguide 11100 for mode conversion, converting from the original TE0 mode to TE2 mode and outputting the seventh optical signal. Similarly, the fifth optical signal, after modulation, undergoes mode conversion via the fifth mode converter 11120, converting from the original TE1 mode to TE0 mode and outputting the eighth optical signal. The eighth optical signal then passes through the fourth return loop waveguide 11130 and enters the sixth mode converter 11140 for mode conversion, changing from the original TE0 mode to TE2 mode and outputting the ninth optical signal. The seventh and ninth optical signals are then phase-modulated again through the upper arm phase modulation region 11030 and lower arm phase modulation region 11040 of the Mach-Zehnder interferometer, respectively. After modulation, the seventh optical signal enters the seventh mode converter 11150 for mode conversion, changing from the original TE2 mode to TE0 mode and outputting the tenth optical signal. The ninth optical signal enters the eighth mode converter 11160 for mode conversion, changing from the original TE2 mode to TE0 mode and outputting the eleventh optical signal. The tenth and eleventh optical signals are input into the 2*2 multimode interference coupler 11170. Based on the phase difference after modulation of the two optical signals, the two output terminals of the multimode interference coupler 11170 will have different output situations, which can realize the output of all light from one output terminal or the output of equal light from both output terminals.Let V1 be the control voltage of the phase modulation zone when light is output from the upper port of the optical switch of the Mach-Zehnder interferometer, V2 be the control voltage of the phase modulation zone when light is output from the lower port of the optical switch of the Mach-Zehnder interferometer, and V3 be the control voltage of the phase modulation zone when light is output from both the upper and lower ports of the optical switch of the Mach-Zehnder interferometer.

[0073] By cascading the proposed mode-multiplexing Mach-Zehnder interferometer optical switches after the two outputs, a larger-scale channel selection and control of the number of working optical paths can be achieved. Taking a three-stage Mach-Zehnder interferometer optical switch as an example, light can be selected from any one of the eight channels for output. For instance, when the control voltages of optical switches 11000, 12000, and 14000 are all V1, light is output from channel 1; when the control voltages of optical switches 11000 and 12000 are V1 and the control voltage of 14000 is V2, light is output from channel 2. The other channels are similar. By controlling the corresponding optical switches in the three-stage cascade, any one of the eight channels can be selected to work, matching the SFP packaged optical module standard.

[0074] The optical switches of the three-stage cascaded Mach-Zehnder interferometer can also be controlled to achieve four outputs. For example, when the control voltage of optical switch 11000 is V1, and the control voltages of 12000, 14000, and 15000 are all V3, the light is split into four, and outputs are simultaneously and equally from channels 1, 2, 3, and 4; when the control voltage of optical switch 11000 is V2, and the control voltages of 13000, 16000, and 17000 are all V3, the light is split into four, and outputs are simultaneously and equally from channels 5, 6, 7, and 8; when the control voltages of optical switches 11000, 14000, and 15 .... When the control voltages for 00 and 16000 are V3, and the control voltages for 12000 and 13000 are V1, light is output simultaneously and equally from channels 1, 2, 5, and 6. When the control voltages for optical switches 11000, 15000, and 17000 are V3, and the control voltages for 12000 and 13000 are V2, light is output simultaneously and equally from channels 3, 4, 7, and 8. The selection states for the remaining channels are similar. By controlling the corresponding optical switches in the three-level cascade, any four of the eight channels can be selected to work, matching the QSFP packaged optical module standard.

[0075] The three-level cascaded Mach-Zehnder interferometer optical switch can also control eight outputs. When the control voltage of the optical switch 11000-17000 is V3, the light is split into eight and output equally from the eight channels, matching the capacity standard of OSFP packaged optical modules.

[0076] As described above, by driving the three-stage cascaded Mach-Zehnder interferometer optical switch with different control voltages, selective switching between eight optical paths can be achieved. In practical applications, the 10000 cascaded Mach-Zehnder interferometer optical switch can achieve 2 nThe state switching of the optical signal, where n is an integer, allows for switching between one, two, four, and eight working optical paths. Further cascading can expand to 16, 32, 64, and more optical paths, enabling channel selection and control. The corresponding working optical signal is modulated by a modulator and then coupled to the optical fiber for transmission via the on-chip optical interface. This achieves dynamic capacity scaling of photonic integrated interconnection, matching different capacity optical module packaging standards to meet the CPO capacity scaling control requirements of dynamic traffic adjustment in data center nodes.

[0077] During the phase modulation process of the entire Mach-Zehnder interferometer optical switch, the optical signal is successively phase-modulated in the upper arm phase modulation region 11030 and the lower arm phase modulation region 11040 of the Mach-Zehnder interferometer in TE0 mode, TE1 mode, and TE2 mode. A total of three phase modulations are performed, which greatly improves the modulation efficiency, thereby reducing the driving voltage required for the optical switch to control the output state of the optical path and realizing low-power control of channel selection, number of channels, and channel rate.

[0078] The basic working principle of this application embodiment is as follows: When an external electric field / external temperature / germanium ion doping is applied, the phase of the transmitted light in the phase modulation region of the upper and lower arms of the Mach-Zehnder interferometer changes. Based on this, the transmission spectral lines of the two output ends of the 2*2 multimode interference coupler 11170 will shift, thus achieving the control of the output light intensity at the two output ends (the light can be fully output from one port, or equally output from both output ends). The optical signal entering the phase modulation region of the upper and lower arms of the Mach-Zehnder interferometer undergoes mode conversion and coupling by the mode converter, and passes through the phase modulation region of the Mach-Zehnder interferometer multiple times as the second, third, fourth, fifth, seventh, and ninth optical signals, respectively. This improves the modulation efficiency and effectively reduces the adjustment voltage for switching the optical output state of the Mach-Zehnder interferometer, thereby reducing the overall power consumption.

[0079] In the description of this application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0080] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. An optical communication device with controllable capacity expansion and contraction, characterized in that, It includes a cascaded Mach-Zehnder interferometer optical switch (10000), a parallel modulator array (20000), an on-chip optical interface array (30000), and an optical fiber array (40000) connected in sequence. The cascaded Mach-Zehnder interferometer optical switch (10000) is composed of multiple Mach-Zehnder interferometer optical switches with the same structure cascaded together. The optical signal input to the cascaded Mach-Zehnder interferometer optical switch (10000) is split into multiple independent optical signals. Multiple optical signals are respectively input to the parallel modulator array (20000) for modulation, and then input to the on-chip optical interface array (30000) and coupled to the optical fiber array (40000) for transmission; The cascaded Mach-Zehnder interferometer optical switch (10000) comprises three cascaded layers: the first layer is the first Mach-Zehnder interferometer optical switch (11000), the second layer is the second Mach-Zehnder interferometer optical switch (12000), the third Mach-Zehnder interferometer optical switch (13000), and the third layer is the fourth Mach-Zehnder interferometer optical switch (14000), the fifth Mach-Zehnder interferometer optical switch (15000), the sixth Mach-Zehnder interferometer optical switch (16000), and the seventh Mach-Zehnder interferometer optical switch (17000). The output terminal of the first Mach-Zehnder interferometer optical switch (11000) is connected to the input terminals of the second Mach-Zehnder interferometer optical switch (12000) and the third Mach-Zehnder interferometer optical switch (13000), respectively. The output terminal of the second Mach-Zehnder interferometer optical switch (12000) is connected to the input terminals of the fourth Mach-Zehnder interferometer optical switch (14000) and the fifth Mach-Zehnder interferometer optical switch (15000), respectively. The output terminal of the third Mach-Zehnder interferometer optical switch (13000) is connected to the input terminals of the sixth Mach-Zehnder interferometer optical switch (16000) and the seventh Mach-Zehnder interferometer optical switch (17000), respectively. The Mach-Zehnder interferometer optical switch includes: an input waveguide (11010), an output waveguide, a 1*2 multimode interference coupler (11020), a 2*2 multimode interference coupler (11170), an upper arm phase modulation region (11030), a lower arm phase modulation region (11040), a first return loop waveguide (11050), a second return loop waveguide (11070), a third return loop waveguide (11100), a fourth return loop waveguide (11130), and eight identical mode converters. The mode converters are used to convert the optical signals input to them into optical signals of different order modes and output them. The mode converters are a first mode converter (11060), a second mode converter (11080), a third mode converter (11090), a fourth mode converter (11110), a fifth mode converter (11120), a sixth mode converter (11140), a seventh mode converter (11150), and an eighth mode converter (11160).

2. The optical communication device with controllable capacity expansion as described in claim 1, characterized in that, The input waveguide (11010) is used to receive the initial first optical signal. The output end of the input waveguide (11010) is connected to the input end of the 1*2 multimode interference coupler (11020). The 1*2 multimode interference coupler (11020) is used to equally split the initial first optical signal to form a second optical signal and a third optical signal. The output end of the 1*2 multimode interference coupler (11020) is respectively connected to the upper arm phase modulation region (11030), the... The lower arm phase modulation region (11040) is connected, and the upper arm phase modulation region (11030) and the lower arm phase modulation region (11040) are used to perform phase modulation on the transmitted optical signal. The output terminals of the upper arm phase modulation region (11030) and the lower arm phase modulation region (11040) are both connected to the input terminal of the 2*2 multimode interference coupler (11170), and the output terminal of the 2*2 multimode interference coupler (11170) is connected to the output waveguide.

3. The optical communication device with controllable capacity expansion as described in claim 2, characterized in that, The two ends of the first return loop waveguide (11050) are respectively connected to the output end of the upper arm phase modulation area (11030) and the input end of the first mode converter (11060). The first mode converter (11060) is used to convert the second optical signal and output it as a fourth optical signal.

4. The optical communication device with controllable capacity expansion as described in claim 3, characterized in that, The third mode converter (11090) is used to convert the fourth optical signal and output it as the sixth optical signal. The two ends of the third return loop waveguide (11100) are respectively connected to the output end of the third mode converter (11090) and the input end of the fourth mode converter (11110). The fourth mode converter (11110) is used to convert the sixth optical signal and output it as the seventh optical signal. The seventh mode converter (11150) is used to convert the seventh optical signal and output it as the tenth optical signal.

5. The optical communication device with controllable capacity expansion as described in claim 4, characterized in that, The two ends of the second return loop waveguide (11070) are respectively connected to the output end of the lower arm phase modulation region (11040) and the input end of the second mode converter (11080). The second mode converter (11080) is used to convert the third optical signal and output it as the fifth optical signal.

6. The optical communication device with controllable capacity expansion as described in claim 5, characterized in that, The fifth mode converter (11120) is used to convert the fifth optical signal and output it as the eighth optical signal. The two ends of the fourth return loop waveguide (11130) are respectively connected to the output end of the fifth mode converter (11120) and the input end of the sixth mode converter (11140). The sixth mode converter (11140) is used to convert the eighth optical signal and output it as the ninth optical signal. The eighth mode converter (11160) is used to convert the ninth optical signal and output it as the eleventh optical signal. The input ends of the 2*2 multimode interference coupler (11170) are respectively input to the tenth optical signal and the eleventh optical signal.

7. The optical communication device with controllable capacity expansion as described in claim 6, characterized in that, The cascaded Mach-Zehnder interferometer optical switch (10000) can achieve 2 n The state switching of the road light signal, where n is an integer.

8. The optical communication device with controllable capacity expansion as described in claim 1, characterized in that, The upper arm phase modulation region (11030) and the lower arm phase modulation region (11040) have the same structure, both including a silicon-based electro-optic phase modulation region, a silicon-based thermo-optic phase modulation region, a silicon-based germanium ion-doped phase modulation region, or a silicon-based deposited phase change material phase modulation region based on ion doping.

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