On-chip nonlinear amplification gain waveguide structure

Abstract

The application provides a chip-on nonlinear amplification gain waveguide structure, which comprises, in sequence, an input waveguide, a first mode converter, a second mode converter, a nonlinear waveguide, a third mode converter and a fourth mode converter; a first signal light is input from the input waveguide to the fourth mode converter, is converted and output as a second signal light by the fourth mode converter, is input from the fourth mode converter to the first mode converter, is converted and output as a third signal light by the second mode converter, is input from the second mode converter to the third mode converter, and is converted and output to an output waveguide by the third mode converter. The application adopts a mode circulation type nonlinear gain amplification waveguide structure composed of multiple mode conversion devices, improves the space utilization of the chip-on waveguide, increases the action length of the optical field and the waveguide, thereby improving the generation efficiency of the nonlinear effect in a unit area, and realizing the effect of amplification gain.

Description

Technical Field

[0001] This invention relates to the field of optoelectronic devices, and more specifically, to an on-chip nonlinear amplification gain waveguide structure. Background Technology

[0002] Nonlinear effects of light are phenomena that generate new optical frequency components due to the nonlinear polarization of a medium under strong light, including the Raman effect, two-photon absorption, and Kerr effect. With the rapid increase in communication speed and data capacity in communication systems, and the rapid development of integrated silicon photonics technology, on-chip nonlinear effects, as a method that can directly realize frequency conversion and multi-wavelength light source generation on the chip without any post-processing of the silicon photonics chip, have wide applications in integrated optical communication, optical sensing, and other fields, and are attracting increasing attention from researchers.

[0003] In promoting the practical application of on-chip nonlinear effects, we need to maximize the generation efficiency and energy conversion efficiency of nonlinear effects while minimizing the space occupied by the corresponding structure on the chip, so that it can generate sufficient nonlinear effects for backend applications within a specific chip size. However, due to the limitations of the waveguide materials themselves, it is difficult to effectively improve the generation efficiency of nonlinear effects within a certain space, whether it is a straight waveguide or a micro-ring nonlinear waveguide.

[0004] To address the issue of enhancing nonlinear effects in waveguides, researchers have proposed a method combining free nanowires with silicon waveguide structures. A Chinese patent with publication number CN114142341A discloses an on-chip supercontinuum light source based on a free nanowire-silicon waveguide structure. The silicon grating is disposed on a SiO2 substrate, which is then placed on an Au film reflective layer. A Si substrate is located at the bottom of the Au film reflective layer. The silicon grating is connected to a first silicon waveguide via a tapered width gradient structure. The first silicon waveguide is connected to one end of a free nanowire via a first free nanowire-silicon waveguide composite structure, and the other end of the free nanowire is connected to a second silicon waveguide via a second free nanowire-silicon waveguide composite structure. This patent proposes using an axially tapered composite waveguide structure to achieve high-efficiency, wide-band optical coupling between the free nanowire and the silicon waveguide, thereby realizing low-power, short-distance, and highly integrated on-chip supercontinuum output. However, due to the need for connecting the free nanowire and the silicon waveguide, as well as additional fabrication processes such as the Au film reflective layer, the structure is relatively complex.

[0005] Therefore, it is urgent to propose new device structures to improve the space utilization of on-chip waveguides, increase the interaction length between the optical field and the waveguide, and improve the generation efficiency of nonlinear effects, so as to promote the practical application of on-chip nonlinear effects. Summary of the Invention

[0006] In view of the shortcomings of the prior art, the purpose of this invention is to provide an on-chip nonlinear amplification gain waveguide structure.

[0007] According to the present invention, an on-chip nonlinear amplification gain waveguide structure includes, in sequence: an input waveguide, a first mode converter, a second mode converter, a nonlinear waveguide, a third mode converter, and a fourth mode converter. Another port of the third mode converter is connected to an output waveguide. Two ports of the fourth mode converter are connected to form a loop. Another port of the first mode converter is connected to another port of the second mode converter to form a loop. A first signal light is input from the input waveguide to the fourth mode converter, and is converted to a second signal light by the fourth mode converter. The second signal light is input from the fourth mode converter to the first mode converter, and is converted to a third signal light by the second mode converter. The third signal light is input from the second mode converter to the third mode converter, and is converted to a third signal light by the third mode converter and output to the output waveguide.

[0008] Preferably, the output terminal of the input waveguide is connected to the first mode converter C port of the first mode converter, the first mode converter B port of the first mode converter is connected to the second mode converter C port of the second mode converter, the second mode converter B port of the second mode converter is connected to the port of the nonlinear waveguide, another port of the nonlinear waveguide is connected to the third mode converter B port of the third mode converter, the third mode converter C port of the third mode converter is connected to the fourth mode converter B port of the fourth mode converter, and the fourth mode converter C port and the fourth mode converter A port of the fourth mode converter are interconnected; the first signal light is transmitted from the input waveguide sequentially through the first mode converter C port, the first mode converter B port, the second mode converter C port, the second mode converter B port, the nonlinear waveguide, the third mode converter B port, the third mode converter C port, the fourth mode converter B port, the fourth mode converter C port, and the fourth mode converter A port to the fourth mode converter, and is converted into the second signal light by the fourth mode converter.

[0009] Preferably, the second signal light is transmitted from the fourth mode converter through the fourth mode converter port B, the third mode converter port C, the third mode converter port B, the nonlinear waveguide, the second mode converter port B, the second mode converter port C, and the first mode converter port B to the first mode converter, and is converted into the second round of the first signal light by the first mode converter.

[0010] Preferably, the first mode converter A port of the first mode converter is connected to the second mode converter A port of the second mode converter. The first signal light of the second round is transmitted from the first mode converter A port through the second mode converter A port to the second mode converter, and is converted into the third signal light by the second mode converter.

[0011] Preferably, the third mode converter A port of the third mode converter is connected to the input end of the output waveguide. The third signal light is transmitted from the second mode converter through the second mode converter B port, the nonlinear waveguide, and the third mode converter B port to the third mode converter. The third mode converter converts the signal light into a third round of first signal light, and the third round of first signal light is transmitted to the output waveguide through the third mode converter A port.

[0012] Preferably, the mode converters used in the first mode converter, the second mode converter, the third mode converter, and the fourth mode converter all include: a first input single-mode waveguide, an input S-shaped waveguide, a single-mode tapered coupling waveguide, an output S-waveguide, an output single-mode waveguide, a second input single-mode waveguide, a multi-mode tapered waveguide, a multi-mode tapered coupling waveguide, and a multi-mode output waveguide; the first input single-mode waveguide corresponds to port A of the mode converter, the multi-mode output waveguide corresponds to port B of the mode converter, the second input single-mode waveguide corresponds to port C of the mode converter, and the output single-mode waveguide corresponds to port D of the mode converter.

[0013] Preferably, the processing material platform for the waveguide structure includes a silicon-based platform.

[0014] Preferably, the first mode converter, the second mode converter, the third mode converter, and the fourth mode converter adopt the same layered structure of mode converter, which includes, from bottom to top, a silicon substrate layer, a silicon dioxide substrate layer, a silicon waveguide layer, and a silicon dioxide top cladding layer.

[0015] Preferably, the silicon waveguide layer includes: a ridge waveguide central region, a ridge waveguide ridge region, a P-type heavily doped region, and an N-type heavily doped region. A first electrode and a second electrode are disposed on the silicon dioxide cladding. The P-type heavily doped regions and N-type heavily doped regions on both sides of the ridge waveguide central region are connected to the first electrode and the second electrode respectively through electrical traces to form a circuit.

[0016] Preferably, the width of the central region of the ridge waveguide is 2000 nm and the height is 150 nm, and the height of the ridge region of the ridge waveguide is 70 nm.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1. This invention employs a nonlinear waveguide, where light reaching a certain power threshold interacts with the waveguide material itself, generating nonlinear effects and amplification gain. By using a mode-cyclic nonlinear gain amplification waveguide structure composed of multiple mode-changing devices, the space utilization of the on-chip waveguide is improved, and the interaction length between the optical field and the waveguide is increased, thereby enhancing the efficiency of nonlinear effect generation per unit area and achieving the amplification gain effect.

[0019] 2. This invention achieves three-round propagation of the signal light within a specific waveguide length by coupling the input signal light into the waveguide structure. This is accomplished through mode conversion and propagation direction reversal via a high-efficiency mode converter, allowing the signal light to propagate in three modes: a first signal light, a second signal light, and a third signal light. This increases the interaction length between the waveguide and the signal light, improves the space utilization of the on-chip waveguide, and effectively enhances the efficiency of nonlinear effects per unit area on the chip. Since the two signal light modes of different orders are independent during transmission, they do not interfere or crosstalk with each other, thus increasing the interaction length between the waveguide and the signal light, improving the space utilization of the on-chip waveguide, and effectively enhancing the efficiency of nonlinear effects.

[0020] 3. By employing a larger waveguide width, this invention can effectively reduce the transmission loss of signal light in the waveguide. At the same time, by applying a reverse bias voltage to the first and second electrodes, it can effectively reduce the nonlinear loss caused by the signal light during transmission, thereby improving the efficiency of nonlinear effect generation and achieving the amplification gain effect. Attached Figure Description

[0021] 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:

[0022] Figure 1 This is a schematic diagram illustrating the structure of the on-chip nonlinear amplification gain waveguide, which is the main feature of this invention.

[0023] Figure 2 This is a schematic diagram illustrating the structure of the mode converter, which is the main feature of this invention.

[0024] Figure 3 This is a schematic cross-sectional view of the on-chip nonlinear amplification gain waveguide, which is the main feature of this invention.

[0025] Figure 4 This invention primarily demonstrates the mode field diagram of the signal light transitioning from TE0 mode to TE1 mode;

[0026] Figure 5This invention primarily demonstrates the conversion efficiency of the signal light conversion process from TE0 mode to TE1 mode as the wavelength varies.

[0027] Figure 6 This invention primarily illustrates the mode field diagram when the signal light in TE0 mode is input from the second input single-mode waveguide in TE0 and TE1 modes.

[0028] Figure 7 This invention primarily demonstrates the mode conversion mode field diagram of the signal light switching from TE0 mode to TE2 mode;

[0029] Figure 8 This invention primarily demonstrates the conversion efficiency of signal light from TE0 mode to TE2 mode as the wavelength varies.

[0030] Figure 9 This invention mainly illustrates the mode field diagram when the signal light of TE0 mode is input from the second input single-mode waveguide in TE0 and TE2 modes.

[0031] As shown in the figure:

[0032] Input waveguide 101 First mode converter 102

[0033] Second mode converter 103 Nonlinear waveguide 104

[0034] Third-mode converter 105 Fourth-mode converter 106

[0035] Output waveguide 107 First input single-mode waveguide 201

[0036] Input S-type waveguide 202; Single-mode tapered coupled waveguide 203

[0037] Output S-waveguide 204; Output single-mode waveguide 205

[0038] Second input single-mode waveguide 206, multi-mode tapered waveguide 207

[0039] Multimode tapered coupled waveguide 208; Multimode output waveguide 209

[0040] 301 Silicon dioxide overcladding ridge waveguide central region 302

[0041] Ridge waveguide ridge region 303 silicon dioxide substrate layer 304

[0042] Silicon substrate layer 305 P-type heavily doped region 306

[0043] N-type heavily doped region 307 First electrode 308

[0044] Second electrode 309 First mode converter C port 1021

[0045] First mode converter A port 1022 First mode converter B port 1023

[0046] Second-mode converter C port 1031 Second-mode converter A port 1032

[0047] Second-mode converter B port 1033; Third-mode converter B port 1051

[0048] Third-mode converter C port 1052; Third-mode converter A port 1053

[0049] Fourth Mode Converter B Port 1061 Fourth Mode Converter C Port 1062

[0050] Fourth Mode Converter A Port 1063 Detailed Implementation

[0051] 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.

[0052] like Figure 1 As shown, an on-chip nonlinear amplification gain waveguide structure according to the present invention includes: an input waveguide 101, a first mode converter 102, a second mode converter 103, a nonlinear waveguide 104, a third mode converter 105, and a fourth mode converter 106. Another port of the third mode converter 105 is connected to an output waveguide 107. Two ports of the fourth mode converter 106 are connected to form a loop. Another port of the first mode converter 102 is connected to another port of the second mode converter 103 to form a loop. A first signal light is input from the input waveguide 101 to the fourth mode converter 106, and is converted to a second signal light by the fourth mode converter 106. The second signal light is input from the fourth mode converter 106 to the first mode converter 102, and is converted to a third signal light by the second mode converter 103. The third signal light is input from the second mode converter 103 to the third mode converter 105, and is converted to a third signal light by the third mode converter 105 and output to the output waveguide 107.

[0053] The on-chip nonlinear amplification gain waveguide structure of this application is a silicon-based gain waveguide structure, or an integrated on-chip gain waveguide structure based on other material platforms with similar structures, and is not limited to silicon-based platforms. This application improves the space utilization of the on-chip waveguide and increases the interaction length between the optical field and the waveguide by employing a mode-cyclic nonlinear gain amplification waveguide structure composed of mode-changing devices, thereby improving the generation efficiency of nonlinear effects per unit area and achieving the amplification gain effect.

[0054] Input waveguide 101 receives the initial signal light, i.e., the first signal light, from the fiber optic input chip and inputs it to the first mode converter 102. The first mode converter 102 converts the second signal light, which has completed one foldback and two rounds of transmission, to the second mode converter 103 and completes the second foldback. The second mode converter 103 converts the first signal light, which has completed two foldbacks and two rounds of transmission, to the third signal light and starts the third round of transmission. The nonlinear waveguide 104, whose waveguide material interacts with the signal light to produce a nonlinear effect, achieves the effect of amplification gain. The third mode converter 105 converts the third signal light, which has completed two foldbacks and three rounds of transmission, to the third mode and outputs the first signal light to the output waveguide 107. The fourth mode converter 106 converts the first signal light, which has completed one round of transmission, to the second mode and completes the first foldback, and starts the second round of transmission. The output waveguide 107 outputs the signal light, which has completed three rounds of transmission, at which point the signal light is restored to the first signal light.

[0055] This application involves three transmission processes, with the first signal light, second signal light, and third signal light operating in the first mode, second mode, and third mode, respectively. It should be noted that the first mode, second mode, and third mode can be any optical waveguide mode. The following explanation will only use the case where the first mode is TE0, the second mode is TE1, and the third mode is TE2 as an example.

[0056] The signal light enters the waveguide structure in TE0 mode, i.e., the first signal light state, and first passes through and interacts with the nonlinear waveguide 104. The first signal light then passes through the fourth mode converter 106, changing from TE0 mode to TE1 mode, outputting the second optical signal. It then passes through the nonlinear waveguide 104 a second time and interacts with it. The second signal light passes through the first mode converter 102 and the second mode converter 103, changing from TE1 mode to TE2 mode, outputting the third optical signal. It then passes through the nonlinear waveguide 104 a third time and interacts with it. The third signal light passes through the third mode converter 105, changing from TE2 mode to TE0 mode, and is finally output from the waveguide structure, completing the amplification and gain effect. During the entire waveguide process, the signal light passes through the nonlinear waveguide 104 three times in TE0, TE1, and TE2 modes, interacting with it three times, increasing the interaction length between the optical field and the waveguide, and improving the efficiency of nonlinear effect generation.

[0057] The basic working principle of this application is as follows: light reaching a certain power threshold interacts with the waveguide material itself, generating nonlinear effects and amplification gain. The input signal light coupled into the waveguide structure undergoes mode conversion and propagation direction reversal by a high-efficiency mode converter, passing through the nonlinear waveguide 104 in the waveguide structure in the modes of the first, second, and third signal lights, respectively. This allows the signal light to propagate in three rounds within a specific length of the waveguide, increasing the interaction length between the waveguide and the signal light, improving the space utilization of the on-chip waveguide, and effectively improving the efficiency of the nonlinear effect per unit area on the chip.

[0058] The first mode converter 102, the second mode converter 103, the third mode converter 105, and the fourth mode converter 106 all have similar structures. The first mode converter 102 and the fourth mode converter 106 include the same structural parameters and are used to complete the mode conversion and optical field reflection between the first signal light and the second signal light. The second mode converter 103 and the third mode converter 105 include the same structural parameters and are used to complete the mode conversion and optical field reflection between the first signal light and the third signal light. Since the two signal lights of different orders are independent of each other during transmission, they do not interfere or crosstalk with each other, thereby achieving the increased interaction length between the waveguide and the signal light mentioned above, improving the space utilization of the on-chip waveguide, and effectively improving the efficiency of nonlinear effects.

[0059] like Figure 2As shown, the first mode converter 102, the second mode converter 103, the third mode converter 105, and the fourth mode converter 106 used for mode conversion output in the three transmission processes have similar structures. The mode converters used in the first mode converter 102, the second mode converter 103, the third mode converter 105, and the fourth mode converter 106 all include: a first input single-mode waveguide 201, an input S-shaped waveguide 202, a single-mode tapered coupling waveguide 203, an output S-waveguide 204, an output single-mode waveguide 205, a second input single-mode waveguide 206, a multimode tapered waveguide 207, a multimode tapered coupling waveguide 208, and a multimode output waveguide 209. The first input single-mode waveguide 201 corresponds to port A of the mode converter, the multimode output waveguide 209 corresponds to port B of the mode converter, the second input single-mode waveguide 206 corresponds to port C of the mode converter, and the output single-mode waveguide 205 corresponds to port D of the mode converter. The main structural difference between the different mode converters lies in the tapered width and length of the two coupling waveguides.

[0060] like Figure 3 As shown, the first mode converter 102, the second mode converter 103, the third mode converter 105, and the fourth mode converter 106 adopt the same layered structure of mode converters, which, from bottom to top, include: a silicon substrate layer 305, a silicon dioxide substrate layer 304, a silicon waveguide layer, and a silicon dioxide upper cladding layer 301. The silicon waveguide layer includes: a ridge waveguide central region 302, a ridge waveguide ridge region 303, a P-type heavily doped region 306, and an N-type heavily doped region 307. A first electrode 308 and a second electrode 309 are disposed on the silicon dioxide upper cladding layer 301. The width of the ridge waveguide central region 302 is 2000 nm, the height is 150 nm, and the height of the ridge waveguide ridge region 303 is 70 nm. The P-type heavily doped region 306 and N-type heavily doped region 307 on both sides of the central region 302 of the ridge waveguide are connected to the first electrode 308 and the second electrode 309 on the top of the chip through electrical traces to form a loop. After applying a reverse bias voltage to the heavily doped region, the nonlinear loss of the waveguide can be reduced.

[0061] In this structure, the larger waveguide width can effectively reduce the transmission loss of signal light in the waveguide. At the same time, if a reverse bias voltage is applied to the first electrode 308 and the second electrode 309, the nonlinear loss caused by the signal light during transmission can be effectively reduced, thereby improving the generation efficiency of nonlinear effects and achieving the effect of amplification gain.

[0062] Taking TE0 and TE1 modes as examples, the process of signal light conversion by the first mode converter 102 is explained. When TE0 mode light enters the first mode converter from the first input single-mode waveguide 201, since the two adjacent waveguides in the coupling region (single-mode tapered coupling waveguide 203 and multi-mode tapered coupling waveguide 208) satisfy the phase matching condition for mode conversion, after the signal light passes through this region, it will be output at the multi-mode tapered coupling waveguide 208 and converted to TE1 mode. Then, it will be output from the multi-mode output waveguide 209, completing the mode conversion function. On the other hand, when TE0 mode signal light is input from the second input single-mode waveguide 206, no mode conversion will occur. It will remain in TE0 mode and be output from the multi-mode output waveguide 209. By reversing the above two processes, based on the reversibility of the optical path, it can be known that when the TE1 mode signal light is input from the multimode output waveguide 209, it will undergo mode conversion in the coupling region, converting to TE0 mode and being output from the first input single-mode waveguide 201; while when the TE0 mode signal light is input from the multimode output waveguide 209, it will not undergo mode conversion in the coupling region and will still be output from the second input single-mode waveguide 206 in TE0 mode.

[0063] like Figure 4-6 The working principle and performance of the first mode converter 102 shown are as follows: Figure 4 This is the mode field diagram for the signal light transitioning from TE0 mode to TE1 mode. Figure 5 As can be seen from the conversion efficiency of this conversion process as the wavelength varies, the first mode converter 102 can effectively complete the conversion between TE0 mode and TE1 mode. Figure 6 The mode field diagram is shown when the signal light in TE0 mode is input through the second input single-mode waveguide 206. As described above, in this case, the signal light does not undergo mode conversion within the first mode converter 102. The conversion process and function of the fourth mode converter 106 operating in TE0 and TE1 modes, and the second and third mode converters 103 and 105 operating in TE0 and TE2 modes are the same as those of the first mode converter 102. The mode conversion mode field diagrams and conversion efficiency curves of the second and third mode converters 103 and 105 are shown below. Figure 7-9 As shown.

[0064] The following explanation, using the first signal light as TE0 mode, the second signal light as TE1 mode, and the third signal light as TE2 mode as examples, illustrates the specific working principle and process of this application: The signal light is input into the input waveguide 101 in the first signal light state (i.e., TE0 mode), and then enters the first mode converter 102 through port C 1021. At this time, the signal light does not undergo mode conversion within the first mode converter 102, but maintains the TE0 mode and is output through port B 1023 of the first mode converter. Subsequently, the signal light enters the second mode converter 103 through port C 1031 of the second mode converter, and still maintains the TE0 mode, being output through port B 1033 of the second mode converter. After the signal light passes through the nonlinear waveguide 104 for the first time and interacts with it, the signal light maintains the TE0 mode and enters the third mode converter 105 through port B 1051 of the third mode converter, and is output through port C 1052 of the third mode converter. Subsequently, the signal light is first input into the fourth mode converter 106 through port B 1061 of the fourth mode converter, and is output from port C 1062 of the fourth mode converter while maintaining TE0 mode, completing the optical path folding back. Then, it is input into the fourth mode converter 106 again through port A 1063 of the fourth mode converter. At this time, a mode conversion will occur, and the signal light will be converted to TE1 mode, becoming the second signal light, and output from port B 1061 of the fourth mode converter, starting the second round of propagation.

[0065] In the second round of propagation, the second signal light maintains the TE1 mode and passes through the third mode converter 105, the nonlinear waveguide 104, and the second mode converter 103, where it interacts with the waveguide for the second time before reaching the first mode converter 102. The signal light is then input into the first mode converter 102 via port B 1023, undergoes mode conversion to TE0 mode, and is output from port A 1022, completing the second optical path folding. Subsequently, it is input into the second mode converter 103 via port A 1032, where it is converted to TE2 mode, becoming the third signal light, and is output from port B 1033, initiating the third round of propagation.

[0066] In the third round of propagation, the third signal light maintains the TE2 mode as it passes through the nonlinear waveguide 104, where it interacts with the waveguide for the third time, and then reaches the third mode converter 105. The signal light is then input into the third mode converter 105 through port B 1051, undergoes mode conversion to become the TE0 mode, becomes the first signal light, and is output through port A 1053 of the third mode converter, thus reaching the output waveguide 107, completing the three rounds of propagation and finally outputting the waveguide structure.

[0067] During its passage through the entire nonlinear amplification and gain waveguide structure, the signal light passes through the nonlinear waveguide 104 three times in TE0, TE1, and TE2 modes, thus interacting with the waveguide three times. Given a fixed length and area occupied by the on-chip waveguide, the structure of this application effectively improves on-chip space utilization and the efficiency of nonlinear effect generation, thereby achieving the amplification and gain effect.

[0068] This application increases the interaction length between the optical field and the waveguide by employing a mode-cyclic waveguide structure, thereby improving the efficiency of nonlinear effect generation. Furthermore, the nonlinear waveguide with this structure can effectively reduce nonlinear loss and improve amplification gain efficiency when a reverse bias voltage is applied.

[0069] 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.

[0070] 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 on-chip nonlinear amplification gain waveguide structure, characterized in that, The system includes, in sequence: an input waveguide (101), a first mode converter (102), a second mode converter (103), a nonlinear waveguide (104), a third mode converter (105), and a fourth mode converter (106). The other port of the third mode converter (105) is connected to an output waveguide (107). The two ports of the fourth mode converter (106) are connected to form a loop. The other port of the first mode converter (102) is connected to the other port of the second mode converter (103) to form a loop. The first signal light is input from the input waveguide (101) to the fourth mode converter (106), and is converted into a second signal light by the fourth mode converter (106). The second signal light is input from the fourth mode converter (106) to the first mode converter (102), and is converted into a third signal light by the second mode converter (103). The third signal light is input from the second mode converter (103) to the third mode converter (105), and is converted into a third signal light by the third mode converter (105) and output to the output waveguide (107). The output of the input waveguide (101) is connected to the first mode converter C port (1021) of the first mode converter (102), the first mode converter B port (1023) of the first mode converter (102) is connected to the second mode converter C port (1031) of the second mode converter (103), the second mode converter B port (1033) of the second mode converter (103) is connected to the port of the nonlinear waveguide (104), the other port of the nonlinear waveguide (104) is connected to the third mode converter B port (1051) of the third mode converter (105), the third mode converter C port (1052) of the third mode converter (105) is connected to the fourth mode converter B port (1061) of the fourth mode converter (106), and the fourth mode converter C port (1062) and the fourth mode converter A port (1063) on the fourth mode converter (106) are interconnected. The first signal light is transmitted from the input waveguide (101) through the first mode converter C port (1021), the first mode converter B port (1023), the second mode converter C port (1031), the second mode converter B port (1033), the nonlinear waveguide (104), the third mode converter B port (1051), the third mode converter C port (1052), the fourth mode converter B port (1061), the fourth mode converter C port (1062), and the fourth mode converter A port (1063) to the fourth mode converter (106), and is converted into the second signal light by the fourth mode converter (106). The second signal light is transmitted from the fourth mode converter (106) sequentially through the fourth mode converter B port (1061), the third mode converter C port (1052), the third mode converter B port (1051), the nonlinear waveguide (104), the second mode converter B port (1033), the second mode converter C port (1031), and the first mode converter B port (1023) to the first mode converter (102), and is converted into the second round of the first signal light by the first mode converter (102). The first mode converter A port (1022) of the first mode converter (102) is connected to the second mode converter A port (1032) of the second mode converter (103). The first signal light of the second round is transmitted from the first mode converter A port (1022) through the second mode converter A port (1032) to the second mode converter (103), and is converted into the third signal light by the second mode converter (103). The third mode converter A port (1053) of the third mode converter (105) is connected to the input terminal of the output waveguide (107). The third signal light is transmitted from the second mode converter (103) through the second mode converter B port (1033), the nonlinear waveguide (104), and the third mode converter B port (1051) to the third mode converter (105). The third mode converter (105) converts the signal light into the first signal light of the third round, and the first signal light of the third round is transmitted to the output waveguide (107) through the third mode converter A port (1053).

2. The on-chip nonlinear amplification gain waveguide structure as described in claim 1, characterized in that, The mode converters used in the first mode converter (102), the second mode converter (103), the third mode converter (105), and the fourth mode converter (106) all include: a first input single-mode waveguide (201), an input S-shaped waveguide (202), a single-mode tapered coupling waveguide (203), an output S-waveguide (204), an output single-mode waveguide (205), a second input single-mode waveguide (206), a multi-mode tapered waveguide (207), a multi-mode tapered coupling waveguide (208), and a multi-mode output waveguide (209); The first input single-mode waveguide (201) corresponds to port A of the mode converter, the multimode output waveguide (209) corresponds to port B of the mode converter, the second input single-mode waveguide (206) corresponds to port C of the mode converter, and the output single-mode waveguide (205) corresponds to port D of the mode converter.

3. The on-chip nonlinear amplification gain waveguide structure as described in claim 1, characterized in that, The processing material platform for the waveguide structure includes a silicon-based platform.

4. The on-chip nonlinear amplification gain waveguide structure as described in claim 1, characterized in that, The first mode converter (102), the second mode converter (103), the third mode converter (105) and the fourth mode converter (106) adopt the same layered structure of mode converters, which include, from bottom to top: silicon substrate layer (305), silicon dioxide substrate layer (304), silicon waveguide layer and silicon dioxide cladding layer (301).

5. The on-chip nonlinear amplification gain waveguide structure as described in claim 4, characterized in that, The silicon waveguide layer includes: a ridge waveguide central region (302), a ridge waveguide ridge region (303), a P-type heavily doped region (306), and an N-type heavily doped region (307). A first electrode (308) and a second electrode (309) are disposed on the silicon dioxide cladding layer (301). The P-type heavily doped region (306) and the N-type heavily doped region (307) on both sides of the ridge waveguide central region (302) are connected to the first electrode (308) and the second electrode (309) respectively through electrical traces to form a circuit.

6. The on-chip nonlinear amplification gain waveguide structure as described in claim 5, characterized in that, The width of the central region (302) of the ridge waveguide is 2000nm and the height is 150nm, and the height of the ridge region (303) of the ridge waveguide is 70nm.

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