On-chip programmable multiplexing waveguide ring based on film lithium niobate

Abstract

The invention discloses an on-chip programmable multiplexing waveguide ring based on thin film lithium niobate, which comprises a thin film lithium niobate chip, a first TE mode straight waveguide, a first polarization beam splitting rotator, a first TE mode bent waveguide, a first polarization independent short waveguide, a first TE / TM mode controllable converter, a second TE mode straight waveguide, a second polarization beam splitting rotator, a second TE mode bent waveguide, a second polarization independent short waveguide and a second TE / TM mode controllable converter are integrated on the thin film lithium niobate chip. Through the structural combination, the programmable multiplexing on-chip integrated waveguide ring function can be realized, so that the functions of adjustable optical delay length, adjustable on-chip integrated waveguide ring and the like can be realized, and the programmable multiplexing on-chip integrated waveguide ring can be widely applied to the fields of microwave photon adjustable optical delay, on-chip optical gyroscopes and the like.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of integrated photonics, and particularly relates to a thin-film lithium niobate-based programmable multiplexed waveguide ring on a chip. BACKGROUND

[0002] Due to the increasing demand for miniaturization and low power consumption of various optoelectronic integrated devices, the development of integrated photonics circuit design, preparation and packaging has been greatly accelerated. As an important component, the on-chip waveguide ring is often integrated with other optical components such as waveguides on the same chip. Through waveguides, optical signals are coupled into waveguide rings to realize functions such as optical processing, transmission and sensing. This integration method can effectively reduce the size and complexity of the optical system and improve the stability and performance of the system.

[0003] Traditional on-chip integrated waveguide ring structures based on silicon light, silicon nitride, thin-film lithium niobate and other technical material platforms have the advantages of small size and on-chip integration, and can be applied to the fields of optical delay, on-chip ring gyroscope, resonant cavity, entangled photon source, photon filtering, optical switch, etc. However, due to the fixed architecture after chip preparation, the traditional on-chip integrated waveguide ring cannot realize adjustable delay when used in the field of optical delay. At the same time, due to the limitation of chip size, the traditional on-chip integrated waveguide ring produces low Sagnac effect when used in the field of on-chip ring gyroscope, which cannot realize high-precision measurement. SUMMARY

[0004] The purpose of the present application is to provide a thin-film lithium niobate-based programmable multiplexed waveguide ring on a chip, which realizes full-chip integration, adjustable delay and precise measurement.

[0005] Technical solution: The on-chip programmable multiplexing waveguide ring based on thin film lithium niobate, comprising a thin film lithium niobate chip, the thin film lithium niobate chip is integrated with a first TE mode straight waveguide, a first polarization beam splitting rotator, a first TE mode curved waveguide, a first polarization independent short waveguide, a first TE / TM mode controllable converter, a second TE mode straight waveguide, a second polarization beam splitting rotator, a second TE mode curved waveguide, a second polarization independent short waveguide and a second TE / TM mode controllable converter; the first TE mode straight waveguide is connected with the No.2 port of the first polarization beam splitting rotator, the No.1 port of the first polarization beam splitting rotator is connected with one end of the first TE / TM mode controllable converter through the first polarization independent short waveguide, the other end of the first TE / TM mode controllable converter is connected with one end of the second TE / TM mode controllable converter through the first TE mode curved waveguide; the second TE mode straight waveguide is connected with the No.2 port of the second polarization beam splitting rotator, the No.1 port of the second polarization beam splitting rotator is connected with the other end of the second TE / TM mode controllable converter through the second polarization independent short waveguide; the No.3 port of the first polarization beam splitting rotator is connected with the No.3 port of the second polarization beam splitting rotator through the second TE mode curved waveguide; when the light passes through the second TE / TM mode controllable converter, the second TE / TM mode controllable converter is voltage regulated according to whether the multiplexing waveguide ring is needed, so that the second TE / TM mode controllable converter outputs TE mode or TM mode light to the No.1 port of the second polarization beam splitting rotator; when the TE mode light is output, the TE mode light enters the second TE mode straight waveguide from the No.2 port of the second polarization beam splitting rotator and is directly output; when the TM mode light is output, the TM mode light is converted into TE mode light in the second polarization beam splitting rotator and then enters the first TE mode curved waveguide from the No.3 port of the second polarization beam splitting rotator to start the multiplexing of the waveguide ring.

[0006] Further, the first TE / TM mode controllable converter comprises a third polarization independent short waveguide, a third polarization beam splitting rotator, a first TE mode waveguide, a multimode interferometer, a metal electrode, a multimode interferometer, a third TE mode straight waveguide; the third polarization independent short waveguide is connected with the No.1 port of the third polarization beam splitting rotator, two first TE mode waveguides are connected with the third polarization beam splitting rotator and the multimode interferometer on both sides, the other end of the multimode interferometer is connected with the third TE mode straight waveguide; the multimode interferometer and the two first TE mode waveguides between the multimode interferometers are provided with metal electrodes; through the setting of the first TE / TM mode controllable converter, the conversion of TE / TM mode light can be realized.

[0007] Further, the voltage loaded on the metal electrode is changed to change the transmission path of the light, so that the light enters the 2nd or 3rd port of the third polarization beam splitting rotator.

[0008] When the high-level voltage is loaded on the metal electrode, the TE mode light enters the third polarization beam splitting rotator along the first TE mode waveguide connected with the 2nd port of the third polarization beam splitting rotator, and the light keeps the TE mode after passing through the third polarization beam splitting rotator and enters the third polarization independent short waveguide.

[0009] Further, when the low-level voltage is loaded on the metal electrode, the TE mode light enters the third polarization beam splitting rotator along the first TE mode waveguide connected with the 3rd port of the third polarization beam splitting rotator, and the TE mode light is converted to TM mode light in the third polarization beam splitting rotator, thereby realizing the on-demand conversion of the TE / TM mode light.

[0010] Further, by shortening the lengths of the first polarization independent short waveguide and the second polarization independent short waveguide, the TE / TM mode loss difference and the TE / TM mode dispersion effect are reduced.

[0011] Further, the first TE / TM mode controllable converter and the second TE / TM mode controllable converter are structurally identical.

[0012] Further, the first TE / TM mode controllable converter and the second TE / TM mode controllable converter determine whether to perform the TE / TM mode conversion according to whether the waveguide ring needs to be reused.

[0013] During the multiplexing waveguide ring process, the first TE / TM mode controllable converter converts the TM mode light output by the 1st port of the first polarization beam splitting rotator to TE mode and inputs it to the first TE mode straight waveguide.

[0014] The first TE mode straight waveguide and the second TE mode straight waveguide are arranged in parallel, and the first polarization independent short waveguide and the second polarization independent short waveguide are arranged in parallel.

[0015] Beneficial effects: Compared with the prior art, the significant technical effects of the present application are as follows: (1) the full-chip integrated optical device of the present patent controls the polarization of light through the cooperation of the first and second polarization beam splitting rotators and the first and second TE / TM mode controllable converters and the first TE mode bending waveguide, thereby realizing controllable multiplexing of the waveguide ring structure, so that the optical path has the function of flexible adjustment, avoiding the need for multiple chip preparation to meet the complex and high-cost flow process of different optical paths; (2) all devices are integrated on a thin film lithium niobate chip in the present application, and a full-chip integrated optical device is constructed. This full-chip integrated manner greatly reduces the chip size, and through multiple multiplexing waveguide rings, the Sagnac effect in a unit area can be effectively amplified, thereby improving the precision of the on-chip optical gyroscope; (3) the on-chip programmable multiplexing waveguide ring of the present application can realize polarization conversion and convert the incident TE mode light into TE / TM mode output of any ratio. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 is a structural schematic diagram of the present application;

[0017] Figure 2 is a structural schematic diagram of the first TE / TM mode controllable converter in the present application. DETAILED DESCRIPTION

[0018] As shown in Figure 1 the present application, the on-chip programmable multiplexing waveguide ring based on thin film lithium niobate includes a thin film lithium niobate chip 11, a first TE mode straight waveguide 1, a first polarization beam splitting rotator 2, a first TE mode bending waveguide 3, a first polarization independent short waveguide 4, a first TE / TM mode controllable converter 5, a second TE mode straight waveguide 6, a second polarization beam splitting rotator 7, a second TE mode bending waveguide 8, a second polarization independent short waveguide 9, and a second TE / TM mode controllable converter 10 integrated on the thin film lithium niobate chip 11. The first TE mode straight waveguide 1, the first polarization beam splitting rotator 2, the first TE mode bending waveguide 3, the first polarization independent short waveguide 4, the first TE / TM mode controllable converter 5, the second TE mode straight waveguide 6, the second polarization beam splitting rotator 7, the second TE mode bending waveguide 8, the second polarization independent short waveguide 9, and the second TE / TM mode controllable converter 10 are all prepared on the thin film lithium niobate chip 11 by a semiconductor process. Specifically, the thin film lithium niobate on-chip programmable multiplexing waveguide ring chip of the present application integrates optical functional devices of different topographies onto the chip through steps such as exposure, development, etching, deposition, and windowing. The first TE mode straight waveguide 1 and the second TE mode straight waveguide 6 only support TE mode light transmission and have a high polarization extinction ratio.

[0019] The first polarization splitting and rotating device 2 and the second polarization splitting and rotating device 7 are both three-port devices, having a No. 1 port, a No. 2 port and a No. 3 port. Taking the second polarization splitting and rotating device 7 as an example, light incident from the No. 1 port will be output from the No. 2 port if the light is in a TE mode, or will be converted to a TE mode in the second polarization splitting and rotating device 7 and then output from the No. 3 port if the light is in a TM mode. When TE mode light is incident from one port (the No. 2 port or the No. 3 port) of the double-port side, the light will be output from the single-port side (i.e. the No. 1 port) in a TE mode or converted to a TM mode according to the incident port position. Specifically, when TE mode light is incident from the No. 2 port (including a straight-through waveguide) of the first polarization splitting and rotating device 2, the light will be output from the No. 1 port in a TE mode; when TE mode light is incident from the No. 3 port (not a straight-through waveguide) of the first polarization splitting and rotating device 2, the light will be output from the No. 1 port in a TM mode.

[0020] The functions of the first TE mode curved waveguide 3 and the second TE mode curved waveguide 8 are to transmit light along the curved waveguide while maintaining the TE mode characteristics of the light. The function of the first polarization-independent short waveguide 4 is to connect the TE or TM light mode transmission of the first polarization splitting and rotating device 2 to the first TE / TM mode controllable converter 5. The function of the second polarization-independent short waveguide 9 is to connect the TE or TM light mode transmission of the second polarization splitting and rotating device 7 to the second TE / TM mode controllable converter 10. By shortening the lengths of the first polarization-independent short waveguide 4 and the second polarization-independent short waveguide 9, the TE / TM mode loss difference and the TE / TM mode dispersion effect are reduced, and the lengths of the first polarization-independent short waveguide 4 and the second polarization-independent short waveguide 9 are not more than 500 microns.

[0021] The functions of the first TE / TM mode controllable converter 5 and the second TE / TM mode controllable converter 10 are as follows: whether to perform TE / TM light mode conversion is determined according to whether the waveguide ring needs to be reused. When the waveguide ring needs to be reused, the light needs to pass through the first TE / TM mode controllable converter 5 and the second TE / TM mode controllable converter 10 once for mode conversion. The first TE / TM mode controllable converter 5 and the second TE / TM mode controllable converter 10 form a pair to realize the programmable multiplexing waveguide ring function.

[0022] The specific arrangement of the above components is as follows:

[0023] The first TE mode straight waveguide 1 is connected to the No. 2 port of the first polarization splitting and rotating device 2, the No. 1 port of the first polarization splitting and rotating device 2 is connected to one end of the first TE / TM mode controllable switch 5 through the first polarization independent short waveguide 4, and the other end of the first TE / TM mode controllable switch 5 is connected to one end of the second TE / TM mode controllable switch 10 through the first TE mode bending waveguide 3. The second TE mode straight waveguide 6 is connected to the No. 2 port of the second polarization splitting and rotating device 7, and the No. 1 port of the second polarization splitting and rotating device 7 is connected to the other end of the second TE / TM mode controllable switch 10 through the second polarization independent short waveguide 9. The No. 3 port of the first polarization splitting and rotating device 2 is connected to the No. 3 port of the second polarization splitting and rotating device 7 through the second TE mode bending waveguide 8. The first TE mode straight waveguide 1 is arranged in parallel with the second TE mode straight waveguide 6, and the first polarization independent short waveguide 4 is arranged in parallel with the second polarization independent short waveguide 9.

[0024] When the light passes through the second TE / TM mode controllable switch 10, the second TE / TM mode controllable switch 10 outputs the light in the TE mode or the TM mode to the No. 1 port of the second polarization splitting and rotating device 7 according to whether the multiplexing waveguide ring is needed or not, and specifically, when the multiplexing waveguide ring is not needed, the second TE / TM mode controllable switch 10 outputs the light in the TE mode to the No. 1 port of the second polarization splitting and rotating device 7; when the multiplexing waveguide ring is needed, the second TE / TM mode controllable switch 10 outputs the light in the TM mode to the No. 1 port of the second polarization splitting and rotating device 7.

[0025] When the second TE / TM mode controllable switch 10 outputs the light in the TE mode to the No. 1 port of the second polarization splitting and rotating device 7, the light in the TE mode enters the second TE mode straight waveguide 6 from the No. 2 port of the second polarization splitting and rotating device 7 and is directly outputted;

[0026] When the second TE / TM mode controllable switch 10 outputs the light in the TM mode to the No. 1 port of the second polarization splitting and rotating device 7, the light in the TM mode is converted into the light in the TE mode in the second polarization splitting and rotating device 7 and then enters the first TE mode bending waveguide 3 from the No. 3 port of the second polarization splitting and rotating device 7 to start the multiplexing of the waveguide ring.

[0027] It is worth noting that the first TE mode straight waveguide 1 and the second TE mode straight waveguide 6 can both serve as the incident and exit waveguide for light transmission. Specifically, when the first TE mode straight waveguide 1 serves as the incident waveguide for light transmission, the second TE mode straight waveguide 6 serves as the exit waveguide for light transmission; when the second TE mode straight waveguide 6 serves as the incident waveguide for light transmission, the first TE mode straight waveguide 1 serves as the exit waveguide for light transmission. Light incident from the first TE mode straight waveguide 1 and exit from the second TE mode straight waveguide 6 is equivalent to light incident from the second TE mode straight waveguide 6 and exit from the first TE mode straight waveguide 1.

[0028] Since the first TE / TM mode controllable converter 5 and the second TE / TM mode controllable converter 10 are of the same structure and function. Hereinafter, only the structure and function of the first TE / TM mode controllable converter 5 will be introduced.

[0029] As shown in Figure 2 , the first TE / TM mode controllable converter 5 includes a third polarization-independent short waveguide 51, a third polarization splitting rotator 52, a first TE mode waveguide 53, a multimode interferometer 54, a metal electrode 55, a multimode interferometer 56, and a third TE mode straight waveguide 57. The specific arrangement is as follows:

[0030] The third polarization-independent short waveguide 51 is connected to the No. 1 port of the third polarization splitting rotator 52, The two sides of the multimode interferometer 54 are each connected to two first TE mode waveguides 53, and then connected between the third polarization splitting rotator 52 and the multimode interferometer 56, The two sides of the multimode interferometer 54 are each connected to two first TE mode waveguides 53, and then connected between the third polarization splitting rotator 52 and the multimode interferometer 56, The other end of the multimode interferometer 54 is connected to the third TE mode straight waveguide 57. The two first TE mode waveguides 53 between the multimode interferometer 54 and

[0031] The function of the first TE / TM mode controllable converter 5 is to switch the TE / TM optical mode. By changing the voltage loaded on the metal electrode 55 to change the transmission path of light, the light can be switched from The first TE mode waveguide 53 on the left upper side of the multi-mode interferometer 54 or the first TE mode waveguide 53 on the left lower side outputs. Specifically, when a high-level voltage is loaded on the metal electrode 55, the light of the TE mode enters the third polarization beam splitting rotator 52 along the first TE mode waveguide 53 connected with the No. 2 port of the third polarization beam splitting rotator 52, and after passing through the third polarization beam splitting rotator 52, the light remains in the TE mode and enters the third polarization independent short waveguide 51; and when a low-level voltage is loaded on the metal electrode 55, the light of the TE mode enters the third polarization beam splitting rotator 52 along the first TE mode waveguide 53 connected with the No. 3 port of the third polarization beam splitting rotator 52, and the light of the TE mode is converted into light of the TM mode in the third polarization beam splitting rotator 52, thereby realizing on-demand conversion of the TE / TM mode of the light. Therefore, by changing the high and low levels of the voltage loaded on the metal electrode 55, the light mode output from the third polarization beam splitting rotator 52 of the first TE / TM mode controllable converter 5 can be TE or TM mode.

[0032] When the third TE mode straight waveguide 57 integrated on the first TE / TM mode controllable converter 5 is an optical input port, the input light of the TE mode is split at a splitting ratio of 50:50 after being transmitted to the 1*2 multi-mode interferometer 56.

[0033] When the light of the TE mode is incident from the third polarization independent short waveguide 51, the light of the TE mode enters the third polarization beam splitting rotator 52 through the No. 1 port of the third polarization beam splitting rotator 52, and after being incident to the first TE mode waveguide 53 connected with the No. 2 port from the No. 2 port, the light is transmitted backward.

[0034] When the light of the TM mode is incident from the third polarization independent short waveguide 51, the light of the TM mode enters the third polarization beam splitting rotator 52 through the No. 1 port of the third polarization beam splitting rotator 52, and after being converted into light of the TE mode in the third polarization beam splitting rotator 52 and being incident to the first TE mode waveguide 53 connected with the No. 3 port from the No. 3 port, the light is transmitted backward. The first TE mode waveguide 53, The multi-mode interferometer 54, the metal electrode 55, The multi-mode interferometer 56, the third TE mode straight waveguide 57 form a MZ modulator, and by adjusting the voltage on the metal electrode 55, all the energy of the light after the third polarization beam splitting rotator 52 can continue to propagate backward from the third TE mode straight waveguide 57.

[0035] When the light is transmitted to the left from the third TE mode straight waveguide 57, The multi-mode interferometer 56 first divides the light beam energy into 50:50 to verify the waveguide transmission to the left, by adjusting the voltage on the metal electrode 55, so that the light passing through the 2*2 multi-mode interferometer 54 is transmitted from the first TE mode waveguide 53 connected to the second port or the third port to the third polarization beam splitting rotator 52. The light transmitted to the left from the first TE mode waveguide 53 connected to the second port passes through the third polarization beam splitting rotator 52 and remains in the TE mode to the third polarization independent short waveguide 51; the light transmitted to the left from the first TE mode waveguide 53 connected to the third port passes through the third polarization beam splitting rotator 52 and is converted into TM mode to the third polarization independent short waveguide 51.

[0036] During the multiplexing waveguide ring process, the first TE / TM mode controllable converter 5 converts the TM mode light output from the first polarization beam splitting rotator 2 into TE mode and inputs it into the first TE mode curved waveguide 3.

[0037] The TE mode light incident from the first TE mode straight waveguide 1 is transmitted in the clockwise direction, the first polarization beam splitting rotator 2 keeps the TE mode unchanged, and the TE mode light continues to be transmitted through the first polarization independent short waveguide 4, the TE mode light is transmitted to the first TE / TM mode controllable converter 5, and the polarization control is not performed, the light continues to be transmitted in the TE mode through the first TE mode curved waveguide 3 to the second TE / TM mode controllable converter 10. At this time, according to whether the multiplexing waveguide ring needs to be controlled, the output mode of the second TE / TM mode controllable converter 10 is adjusted to realize the multiplexing function.

[0038] If the multiplexing waveguide ring is not needed, the TE mode light needs to be kept unchanged, at this time, by loading high level voltage on the metal electrode 55, the second TE / TM mode controllable converter 10 outputs TE mode light, the TE mode light enters from the first port of the second polarization beam splitting rotator 7 after passing through the second polarization independent short waveguide 9, and is output from the second port through the second TE mode straight waveguide 6;

[0039] If the waveguide ring needs to be multiplexed, i.e. the light needs to be transmitted along the second TE mode bending waveguide 8 to continue to transmit one more round along the structure, the second TE / TM mode controllable converter 10 outputs the TM mode light by loading a low-level voltage on the metal electrode 55, the TM mode light enters the second polarization-independent short waveguide 9 from the No. 1 port of the second polarization beam splitter rotator 7, is converted into the TE mode light and then enters the second TE mode bending waveguide 8 from the No. 3 port, then the TE mode light enters the first polarization beam splitter rotator 2 from the No. 3 port of the first polarization beam splitter rotator 2, is converted into the TM mode light and then exits from the No. 1 port, the TM mode light continues to transmit to the first TE / TM mode controllable converter 5 through the first polarization-independent short waveguide 4, at this time, the first TE / TM mode controllable converter 5 converts the TM mode light into the TE mode light and then continues to transmit clockwise along the first TE mode bending waveguide 3. After being transmitted to the second TE / TM mode controllable converter 10, according to whether the waveguide ring structure needs to be multiplexed or not, the TE or TM mode can be controlled, the TE mode is directly transmitted outward, and the TM mode is converted and then continues to be multiplexed. Therefore, by configuring the TE / TM mode controllable converter 5, the programmable multiplexed waveguide ring function can be realized.

[0040] The present application can realize the programmable multiplexed on-chip integrated waveguide ring function by combining all the structures on the thin film lithium niobate chip, can realize the functions of adjustable optical delay length and adjustable on-chip integrated waveguide ring, and can be widely applied in the fields of microwave photon adjustable optical delay, on-chip optical gyroscope and the like.

Claims

1. An on-chip programmable multiplexed waveguide ring based on thin-film lithium niobate, characterized in that: The device includes a thin-film lithium niobate chip (11), on which the thin-film lithium niobate chip (11) integrates a first TE mode straight waveguide (1), a first polarization beam splitter (2), a first TE mode bent waveguide (3), a first polarization-independent short waveguide (4), a first TE / TM mode controllable converter (5), a second TE mode straight waveguide (6), a second polarization beam splitter (7), a second TE mode bent waveguide (8), a second polarization-independent short waveguide (9), and a second TE / TM mode controllable converter (10). The first TE mode straight waveguide (1) is connected to port 2 of the first polarization beam splitter (2), and port 1 of the first polarization beam splitter (2) is connected to one end of the first TE / TM mode controllable converter (5) through the first polarization-independent short waveguide (4). The other end of the first TE / TM mode controllable converter (5) is connected to one end of the second TE / TM mode controllable converter (10) through the first TE mode bent waveguide (3). The second TE mode straight waveguide (6) is connected to port 2 of the second polarization beam splitter (7), and port 1 of the second polarization beam splitter (7) is connected to the other end of the second TE / TM mode controllable converter (10) through the second polarization-independent short waveguide (9). The third port of the first polarization beam splitter (2) is connected to the third port of the second polarization beam splitter (7) through a second TE mode bent waveguide (8); When light passes through the second TE / TM mode controllable converter (10), the voltage of the second TE / TM mode controllable converter (10) is adjusted according to whether the waveguide ring needs to be reused, so that the second TE / TM mode controllable converter (10) outputs TE mode or TM mode light to port 1 of the second polarization beam splitter (7); When outputting TE mode light, the TE mode light enters the second TE mode straight waveguide (6) directly from port 2 of the second polarization beam splitter (7) and is output directly; when outputting TM mode light, the TM mode light is converted into TE mode light in the second polarization beam splitter (7) and then enters the first TE mode curved waveguide (3) from port 3 of the second polarization beam splitter (7) to start the multiplexing of the waveguide ring.

2. The on-chip programmable multiplexed waveguide ring based on thin-film lithium niobate according to claim 1, characterized in that: The first TE / TM mode controllable converter (5) includes a third polarization-independent short waveguide (51), a third polarization beam splitter (52), and a first TE mode waveguide (53). Multimode interferometer (54), metal electrode (55) Multimode interferometer (56), third TE mode straight waveguide (57); The third polarization-independent short waveguide (51) is connected to port 1 of the third polarization beam splitter (52). The multimode interferometer (54) is connected to two first TE mode waveguides (53) on each side, and then connected to the third polarization beam rotator (52) and Between the multimode interferometers (56), The other end of the multimode interferometer (56) is connected to the third TE mode straight waveguide (57); The 2*2 multimode interferometer (54) and Metal electrodes (55) are placed on the two first TE mode waveguides (53) between the multimode interferometers (56).

3. The on-chip programmable multiplexed waveguide ring based on thin-film lithium niobate according to claim 2, characterized in that: The transmission path of light is changed by changing the voltage applied to the metal electrode (55).

4. The on-chip programmable multiplexed waveguide ring based on thin-film lithium niobate according to claim 3, characterized in that: When a high-level voltage is applied to the metal electrode (55), the TE mode light will enter the third polarization beam splitter (52) along the first TE mode waveguide (53) connected to port 2 of the third polarization beam splitter (52). After passing through the third polarization beam splitter (52), the light will remain in the TE mode and enter the three polarization-independent short waveguide (51).

5. The on-chip programmable multiplexed waveguide ring based on thin-film lithium niobate according to claim 3, characterized in that: When a low-level voltage is applied to the metal electrode (55), TE mode light will enter the third polarization beam splitter (52) along the first TE mode waveguide (53) connected to port 3 of the third polarization beam splitter (52). The TE mode light is converted into TM mode light in the third polarization beam splitter (52), thereby realizing the on-demand conversion of TE / TM mode of light.

6. The on-chip programmable multiplexed waveguide ring based on thin-film lithium niobate according to claim 1, characterized in that: The difference in TE / TM mode loss and the effect of TE / TM mode dispersion are reduced by shortening the lengths of the first polarization-independent short waveguide (4) and the second polarization-independent short waveguide (9).

7. The on-chip programmable multiplexed waveguide ring based on thin-film lithium niobate according to claim 1, characterized in that: The first TE / TM mode controllable converter (5) and the second TE / TM mode controllable converter (10) have the same structure.

8. The on-chip programmable multiplexed waveguide ring based on thin-film lithium niobate according to claim 7, characterized in that: The first TE / TM mode controllable converter (5) and the second TE / TM mode controllable converter (10) determine whether to perform TE / TM optical mode conversion based on whether the waveguide ring needs to be reused.

9. The on-chip programmable multiplexed waveguide ring based on thin-film lithium niobate according to claim 1, characterized in that: During the multiplexing of the waveguide ring, the first TE / TM mode controllable converter (5) converts the TM mode light output from port 1 of the first polarization beam splitter (2) into TE mode and then inputs it into the first TE mode curved waveguide (3).

10. The on-chip programmable multiplexed waveguide ring based on thin-film lithium niobate according to claim 1, characterized in that: The first TE mode straight waveguide (1) and the second TE mode straight waveguide (6) are arranged in parallel, and the first polarization-independent short waveguide (4) and the second polarization-independent short waveguide (9) are arranged in parallel.

Images