WO2016145641A1

WO2016145641A1 - Component and method for converting modulation format of optical signal

Info

Publication number: WO2016145641A1
Application number: PCT/CN2015/074551
Authority: WO
Inventors: 王健; 桂成程; 王大伟
Original assignee: 华为技术有限公司
Priority date: 2015-03-19
Filing date: 2015-03-19
Publication date: 2016-09-22
Also published as: CN107210816A; CN107210816B

Abstract

Provided are a component and method for converting the modulation format of optical signals. The component comprises a first nonlinear silicon-based optical waveguide, a first MMI, a second MMI, and a third MMI. The first MMI divides a first light pulse into a first light pulse beam and a second light pulse beam. The second MMI is used for coupling two OOK optical signals with one of the light pulse beams into a first coupled optical signal. The third MMI is used for coupling another two OOK optical signals with the other of the light pulse beams into a second coupled optical signal. The first nonlinear silicon-based optical waveguide cross-phase modulates the first coupled optical signal into a first QPSK optical signal and cross-phase modulates the second coupled optical signal into a second QPSK optical signal. The first MMI synthesizes the first QPSK optical signal and the second QPSK optical signal into a first 16-QAM optical and outputs same. The described technical solution increases the rate of conversion of the modulation format of optical signals.

Description

Device and method for converting modulation pattern of optical signal

Technical field

Embodiments of the present invention relate to the field of optical communications and, more particularly, to a device and method for converting a modulation pattern of an optical signal.

Background technique

On-off keying (OOK) patterns are widely used in network scenarios such as local area networks for low-speed transmission. Compared with the binary modulation pattern, one symbol of the high-order modulation pattern can indicate more signal states, so that the capacity of information transmission can be greatly increased, thereby realizing higher bits with the same baud rate. rate. High-order modulation patterns are often used in network scenarios such as backbone networks where high-speed transmission is required.

When an optical signal is transmitted from a local area network to a backbone network, it needs to undergo a conversion process from a binary modulation pattern to a high-order modulation pattern. The conventional conversion method is to use a Four Wave Mixing (FWM) phenomenon in a Semiconductor Optical Amplifier (SOA) to convert two OOK optical signals (for example, a first OOK optical signal and a second OOK optical signal). Converted into a Quadrature Phase Shift Keying (QPSK) optical signal. Then, a Quaternary Amplitude Modulation (QAM) optical signal is synthesized by two QPSK optical signals. The specific process of converting two OOK optical signals (for example, the first OOK optical signal and the second OOK optical signal) into one QPSK optical signal is as follows: the first OOK optical signal first enters the first SOA with two different wavelengths of auxiliary light. In the device, a Binary Phase Shift Keying (BPSK) optical signal is generated, and then the BPSK optical signal, the second OOK optical signal, and the third auxiliary light of different wavelengths are input into the SOA device to generate a QPSK optical signal. This method uses a coupler, a plurality of SOAs, and a plurality of auxiliary lights to realize modulation of a modulation pattern of an optical signal. The device structure is relatively complicated, and the modulation pattern of the optical signal has a slow conversion rate.

Summary of the invention

Embodiments of the present invention provide a device and method for converting a modulation pattern of an optical signal, which can improve a modulation pattern conversion rate of an optical signal.

In a first aspect, a device for converting a modulation pattern of an optical signal includes: a first nonlinear silicon-based optical waveguide, a first multimode interference optical coupler MMI, a second MMI, and a third MMI; The first MMI and the second MMI are connected by a first silicon-based optical waveguide, the first MMI and the third MMI are connected by a first silicon-based optical waveguide, the first nonlinear silicon-based optical waveguide and the The second MMI is connected by a first silicon-based optical waveguide, and the first nonlinear silicon-based optical waveguide is connected to the third MMI by a first silicon-based optical waveguide; the first MMI is configured to receive a first optical pulse, And splitting the first light pulse to obtain a first light pulse and a second light pulse; the second MMI is configured to receive the first OOK light signal, the second OOK light signal, and the first light pulse And coupling the first OOK optical signal, the second OOK optical signal, and the first optical pulse to obtain a first coupled optical signal; the third MMI is configured to receive a third OOK optical signal, a fourth OOK optical signal and the second optical pulse, and coupling the third OOK optical signal, the fourth OOK optical signal, and the second optical pulse to obtain a second coupled optical signal; The first nonlinear silicon-based optical waveguide is configured to use the first OOK optical signal and the second OOK light in the first coupled optical signal And performing cross-phase modulation with the first beam of light to obtain a first quadrature phase shift keying QPSK optical signal, wherein the first nonlinear silicon-based optical waveguide is further used in the second coupled optical signal Performing cross-phase modulation on the third OOK optical signal, the fourth OOK optical signal, and the second optical pulse to obtain a second QPSK optical signal; the first QPSK signal reaching the a first MMI, the second QPSK signal reaching the first MMI through the second MMI; the first MMI is further configured to synthesize the first QPSK optical signal and the second QPSK optical signal, A first 16-quadrature amplitude modulated QAM optical signal is obtained, and the first 16-QAM optical signal is output.

In conjunction with the first aspect, in an implementation of the first aspect, the first MMI is further configured to split the first optical pulse, including the first light according to a power of the first optical pulse Pulse splitting, wherein a ratio of a power of the first beam of light pulses to a power of the second beam of light pulses is 2:1; the first of the first coupled optical signals is of the first OOK optical signal The ratio of the power to the power of the second OOK optical signal is 2:1; the ratio of the power of the third OOK optical signal to the power of the fourth OOK optical signal in the second coupled optical signal is 2 :1.

In combination with the first aspect and the foregoing implementation manner, in another implementation manner of the first aspect, the device further includes: a fourth MMI, a fifth MMI, a sixth MMI, a seventh MMI, and a second nonlinear silicon-based light. a waveguide and a two-dimensional photonic crystal grating; the first MMI and the fourth MMI are connected by a first silicon-based optical waveguide, and the fourth MMI and the fifth MMI are connected by a first silicon-based optical waveguide, The fifth MMI is connected to the sixth MMI by a first silicon-based optical waveguide, the fifth MMI is connected to the seventh MMI by a first silicon-based optical waveguide, and the second nonlinear silicon-based optical waveguide is Narrative The six MMIs are connected by a first silicon-based optical waveguide, and the second nonlinear silicon-based optical waveguide is connected to the seventh MMI by a first silicon-based optical waveguide, the first MMI and the two-dimensional photonic crystal grating a first silicon-based optical waveguide connected, the fifth MMI being coupled to the two-dimensional photonic crystal grating by a first silicon-based optical waveguide; and the fourth MMI for receiving a light pulse from a pulse generator and receiving The power of the light pulse is split to obtain the first light pulse and the second light pulse; the fifth MMI is for receiving the second light pulse, and splitting the second light pulse to obtain a third light pulse and a fourth light pulse; the sixth MMI is configured to receive the fifth OOK light signal, the sixth OOK light signal, and the third light pulse, and the fifth OOK light signal, the The sixth OOK optical signal and the third optical pulse are coupled to obtain a third coupled optical signal; the seventh MMI is configured to receive the seventh OOK optical signal, the eighth OOK optical signal, and the fourth optical pulse, and Coupling the seventh OOK optical signal, the eighth OOK optical signal, and the fourth optical pulse, a fourth coupled optical signal; the second nonlinear silicon-based optical waveguide is configured to use the fifth OOK optical signal, the sixth OOK optical signal, and the third beam of the third coupled optical signal The optical pulse is cross-phase modulated to obtain a third QPSK optical signal, and the second nonlinear silicon-based optical waveguide is further configured to use the seventh OOK optical signal in the fourth coupled optical signal, the eighth OK The optical signal and the fourth optical pulse are cross-phase modulated to obtain a fourth QPSK optical signal; the third QPSK signal reaches the fifth MMI through the seventh MMI, and the fourth QPSK signal passes the The sixth MMI reaches the fifth MMI; the fifth MMI is further configured to synthesize the third QPSK optical signal and the fourth QPSK optical signal to obtain a second 16-QAM optical signal, and output the first a two-six-QAM optical signal; the two-dimensional photonic crystal grating is configured to receive a first 16-QAM optical signal output by the first MMI and a second 16-QAM optical signal output by the fifth MMI, and Coupling the first 16-QAM optical signal and the second 16-QAM optical signal to obtain a polarization multiplexed PDM-16-QAM optical signal

In conjunction with the first aspect and the foregoing implementation manner, in another implementation manner of the first aspect, the first MMI, the second MMI, the third MMI, the fifth MMI, and the sixth The MMI and the seventh MMI are asymmetric MMIs, and the fourth MMI is a symmetric MMI.

In conjunction with the first aspect and the foregoing implementation manner, in another implementation manner of the first aspect, a ratio of a power of the first optical pulse to a power of the second optical pulse is 1:1; The MMI is further configured to split the second optical pulse, comprising splitting the second optical pulse according to a power of the second optical pulse, wherein a power of the third optical pulse is the same as the first The ratio of the power of the four optical pulses is 2:1; the power of the fifth OOK optical signal in the third coupled optical signal The ratio of the power of the sixth OOK optical signal is 2:1; the ratio of the power of the seventh OOK optical signal to the power of the eighth OK optical signal in the fourth coupled optical signal is 2: 1.

In conjunction with the first aspect and the foregoing implementation manner, in another implementation manner of the first aspect, the fourth MMI is a 1*2 MMI coupler, and the first MMI and the fifth MMI are 2* The MMI coupler of 2, the second MMI, the third MMI, the sixth MMI, and the seventh MMI are 1*3 MMI couplers.

In conjunction with the first aspect and the above implementation thereof, in another implementation of the first aspect, the first nonlinear silicon-based optical waveguide and the second nonlinear silicon-based optical waveguide have a cross-phase modulation effect.

In combination with the first aspect and the foregoing implementation manner, in another implementation manner of the first aspect, the first nonlinear silicon-based optical waveguide or the second nonlinear silicon-based optical waveguide is any one of the following waveguides Species: ridge waveguide, slot waveguide, slab waveguide, and photonic crystal waveguide.

In conjunction with the first aspect and the foregoing implementation manner, in another implementation manner of the first aspect, the device is disposed in a first network node, where the first OOK optical signal and the second OOK are An optical signal, the third OOK optical signal, the fourth OOK optical signal, the fifth OOK optical signal, the sixth OOK optical signal, the seventh OOK optical signal, and the eighth OOK optical signal Generating by electrical signal modulation of the first network node; or the first OOK optical signal, the second OOK optical signal, the third OOK optical signal, the fourth OOK optical signal, the fifth The OOK optical signal, the sixth OOK optical signal, the seventh OOK optical signal, and the eighth OK optical signal are generated by a second network node and transmitted by the second network node to the first network node.

In conjunction with the first aspect and the above implementation thereof, in another implementation of the first aspect, the device is disposed on a silicon wafer.

In a second aspect, there is provided a method of modulation pattern conversion of an optical signal, the method being used for a device for optical signal modulation pattern conversion, the device comprising a first nonlinear silicon-based optical waveguide, a first multimode interference An optical coupler MMI, a second MMI, and a third MMI, wherein the first MMI and the second MMI are connected by a first silicon-based optical waveguide, and the first MMI and the third MMI are first silicon-based light a waveguide connection, the first nonlinear silicon-based optical waveguide is connected to the second MMI by a first silicon-based optical waveguide, and the first nonlinear silicon-based optical waveguide and the third MMI are first silicon-based optical waveguide a waveguide connection, the method comprising: the first MMI receiving a first optical pulse, and splitting the first optical pulse to obtain a first beam of light and a second beam of light; Second MMI Receiving a first OOK optical signal, a second OOK optical signal, and the first optical pulse, and coupling the first OOK optical signal, the second OOK optical signal, and the first optical pulse to obtain a first coupled optical signal; the third MMI receiving a third OOK optical signal, a fourth OOK optical signal, and the second optical pulse, and the third OOK optical signal, the fourth OOK optical signal, and The second beam of light pulses are coupled to obtain a second coupled optical signal; the first nonlinear silicon-based optical waveguide is to be the first OOK optical signal of the first coupled optical signal, the second OOK Performing cross-phase modulation of the optical signal and the first beam of light to obtain a first quadrature phase shift keying QPSK optical signal; the first nonlinear silicon-based optical waveguide to be the one of the second coupled optical signals Performing cross-phase modulation on the third OOK optical signal, the fourth OOK optical signal, and the second optical pulse to obtain a second QPSK optical signal; the first QPSK optical signal reaching the first through the third MMI An MMI, the second QPSK signal reaching the first MMI through the second MMI; the first The MMI synthesizes the first QPSK optical signal and the second QPSK optical signal to obtain a first 16-quadrature amplitude modulated QAM optical signal; the first MMI outputs the first 16-QAM optical signal.

In conjunction with the second aspect, in an implementation of the second aspect, the splitting, by the first MMI, the first optical pulse comprises: the first MMI according to a power of the first optical pulse The first optical pulse is splitting; wherein a ratio of a power of the first optical pulse to a power of the second optical pulse is 2:1; the first OOK in the first coupled optical signal a ratio of a power of the optical signal to a power of the second OOK optical signal is 2:1; a power of the third OOK optical signal in the second coupled optical signal and a power of the fourth OOK optical signal The ratio is 2:1.

With reference to the second aspect and the foregoing implementation manner, in another implementation manner of the second aspect, when the device further includes: a fourth MMI, a fifth MMI, a sixth MMI, a seventh MMI, and a second nonlinear silicon The base optical waveguide and the two-dimensional photonic crystal grating, the method further includes: the fourth MMI receiving the optical pulse emitted by the pulse generator, and splitting the received optical pulse according to the power to obtain the first a light pulse and a second light pulse; the fifth MMI receives the second light pulse, and splits the second light pulse to obtain a first light pulse and a second light pulse; the sixth MMI receiving a fifth OOK optical signal, a sixth OOK optical signal, and the third optical pulse, and coupling the fifth OOK optical signal, the sixth OOK optical signal, and the third optical pulse to obtain a first a third coupled optical signal; the seventh MMI receiving the seventh OOK optical signal, the eighth OOK optical signal, and the fourth optical pulse, and the seventh OOK optical signal, the eighth OOK optical signal, and the The fourth beam of light is coupled to obtain a fourth coupled optical signal; the second non-linear The silicon-based optical waveguide cross-phase-modulates the fifth OOK optical signal, the sixth OOK optical signal, and the third optical pulse in the third coupled optical signal to obtain a third QPSK optical signal; The second nonlinear silicon-based optical waveguide cross-phase-modulates the seventh OOK optical signal, the eighth OOK optical signal, and the fourth optical pulse of the fourth coupled optical signal to obtain a first a fourth QPSK optical signal; the third QPSK signal reaches the fifth MMI through the seventh MMI, and the fourth QPSK signal reaches the fifth MMI through the sixth MMI; the fifth MMI pair Synthesizing the third QPSK optical signal and the fourth QPSK optical signal to obtain a second 16-QAM optical signal; the fifth MMI outputting the second 16-QAM optical signal; the two-dimensional photonic crystal grating receiving a first 16-QAM optical signal output by the first MMI and a second 16-QAM optical signal output by the fifth MMI, and the first 16-QAM optical signal and the second 16-QAM light The signals are coupled to obtain a polarization multiplexed PDM-16-QAM optical signal.

With reference to the second aspect and the foregoing implementation manner, in another implementation manner of the second aspect, a ratio of a power of the first optical pulse to a power of the second optical pulse is 1:1; The MMI is further configured to split the second optical pulse, comprising splitting the second optical pulse according to a power of the second optical pulse, wherein a power of the third optical pulse is the same as the first The ratio of the power of the four optical pulses is 2:1; the ratio of the power of the fifth OOK optical signal to the power of the sixth OOK optical signal in the third coupled optical signal is 2:1; The ratio of the power of the seventh OOK optical signal in the fourth coupled optical signal to the power of the eighth OK optical signal is 2:1.

A device and method for converting a modulation pattern of an optical signal according to an embodiment of the present invention, by splitting an optical pulse using a multimode interference coupler in an all-optical region, coupling two OOK optical signals and one optical pulse, and The use of a silicon-based optical waveguide causes a cross-phase modulation effect of the coupled optical pulse and the two OOK optical signals to generate a QPSK optical signal, and a multi-mode interference coupler can couple the two QPSK optical signals to obtain a 16-QAM optical signal. In order to realize the conversion of the modulation pattern of the optical signal, the rate of conversion of the modulation pattern of the optical signal can be improved.

DRAWINGS

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings to be used in the embodiments of the present invention will be briefly described below. It is obvious that the drawings described below are only some embodiments of the present invention, Those skilled in the art can also obtain other drawings based on these drawings without paying any creative work.

1 is a schematic diagram of a device for converting a modulation pattern of an optical signal according to an embodiment of the present invention.

2 is a schematic diagram of a device for converting a modulation pattern of an optical signal according to another embodiment of the present invention.

3 is a schematic flow chart of a method of converting a modulation pattern of an optical signal according to an embodiment of the present invention.

4 is a schematic flow chart of a method of converting a modulation pattern of an optical signal according to another embodiment of the present invention.

detailed description

The technical solutions in the embodiments of the present invention are clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present invention. It is obvious that the described embodiments are a part of the embodiments of the present invention, but not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of the present invention.

1 is a schematic diagram of a device for converting a modulation pattern of an optical signal according to an embodiment of the present invention. The device of FIG. 1 includes a first multimode interference coupler (MMI) 101, a second MMI 102, a third MMI 103, and a first nonlinear silicon-based optical waveguide 104.

The first MMI and the second MMI are connected by a first silicon-based optical waveguide, the first MMI and the third MMI are connected by a first silicon-based optical waveguide, and the first nonlinear silicon-based optical waveguide and the second MMI are first silicon-based optical waveguide The waveguide is connected, and the first nonlinear silicon-based optical waveguide is connected to the third MMI by the first silicon-based optical waveguide.

The first MMI is for receiving the first light pulse and splitting the power of the first light pulse to obtain a first light pulse and a second light pulse.

The second MMI is used to couple the first OOK optical signal (OOK1 in FIG. 1), the second OOK optical signal (OOK2 in FIG. 1), and the first optical pulse to obtain a first coupled optical signal.

The third MMI is used to couple the third OOK optical signal (OOK3 in FIG. 1), the fourth OOK optical signal (OOK4 in FIG. 1), and the second optical pulse to obtain a second coupled optical signal.

The first nonlinear silicon-based optical waveguide is configured to generate a first OOK optical signal (OOK1 in FIG. 1), a second OOK optical signal (OOK2 in FIG. 1), and a first optical pulse in the first coupled optical signal. Cross-phase modulation effect, obtaining a first QPSK optical signal (QPSK1 in FIG. 1), and the first nonlinear silicon-based optical waveguide is further configured to use a third MMI in the second coupled optical signal to use the third OOK optical signal ( The OOK3), the fourth OOK optical signal (OOK4 in Fig. 1) and the second optical pulse in Fig. 1 are cross-phase modulated to obtain a second QPSK optical signal (QPSK2 in Fig. 1).

The first QPSK optical signal reaches the first MMI through the third MMI, and the second QPSK optical signal reaches the first MMI through the second MMI.

The first MMI is further configured to combine the first QPSK optical signal and the second QPSK optical signal to obtain a first 16-QAM optical signal, and output the first 16-QAM optical signal.

It should be understood that in the embodiment of the present invention, the two-way OOK optical signal and one optical pulse are coupled to obtain a coupled optical signal. The coupling here is to couple two OOK optical signals and a signal input from three ports of a light pulse, and output from one port. The essence of the coupled optical signal is still the original three signals, but can be output from one port after coupling.

The first silicon-based optical waveguide may also be referred to as a silicon-based waveguide line for transmitting light. The first nonlinear silicon-based optical waveguide can be made by adding a nonlinear material to the second silicon-based optical waveguide. It should be understood that the first silicon-based optical waveguide and the second silicon-based optical waveguide are both ordinary silicon-based optical waveguides, and the two may be the same or different.

The Kerr coefficient of the nonlinear material added to the first nonlinear silicon-based optical waveguide is greater than the Kerr coefficient of silicon, and the refractive index of the nonlinear material is smaller than the refractive index of silicon. The present invention does not limit a specific non-linear material. For example, the nonlinear material may be an organic high molecular polymer or the like.

In the embodiment of the present invention, the first MMI, the second MMI, the first nonlinear silicon-based optical waveguide, and the third MMI form a ring structure, so that after the first QPSK optical signal is generated in the first nonlinear silicon-based optical waveguide, The first MMI is reached through the third MMI. Similarly, the second QPSK optical signal can reach the first MMI through the second MMI after being generated in the first nonlinear silicon-based optical waveguide.

The multimode interference coupler MMI can be composed of a wide waveguide and a narrow waveguide, wherein a wide waveguide is used to transmit light and a narrow waveguide is used to form a port of the coupler. The working principle of multimode interference couplers is the self-image effect of multimode waveguides. The MMI achieves splitting and coupling of the optical signal by the self-imaging effect of the optical signal in the waveguide.

Throughout the device, the narrow waveguides on either side of the wide waveguide of the MMI are considered to be symmetric MMIs when symmetric about the wide waveguide used for transmission. Symmetrical MMI can evenly distribute the power of light. For example, a light pulse can be divided into two pulses of equal power by a symmetric MMI. The MMI is considered to be an asymmetric MMI when the position of the narrow waveguide is asymmetric with respect to the wide waveguide. MMI The size of the wide waveguide and the position of the port formed by the narrow waveguide can determine the power distribution ratio of the light passing through the MMI. The asymmetric MMI can distribute the power of the light unevenly. For example, the optical pulse can divide the optical pulse into two optical pulses of different powers through the asymmetric MMI.

The first MMI may be an asymmetric multimode interference coupler, and is further configured to split the first optical pulse according to the power of the first optical pulse to obtain a first optical pulse and a second optical pulse. Wherein, the ratio of the power of the first light pulse to the power of the second light pulse is 2:1.

The first MMI may be a 2*2 MMI coupler, and the second MMI and the third MMI may be a 1*3 MMI coupler. For a 2*2 MMI coupler, one end of the MMI includes two ports and the other end includes two ports. The 1*3 MMI coupler includes one port at one end and three ports at the other end. Signals input from one end port can only be output from the other end port after being processed in the MMI. However, the present invention does not specifically limit the input and output of the port. For example, the same port can be used as an input port or an output port during different optical signal flow directions.

It should be understood that the number of ports and the specific location of the MMI are not limited in the embodiment of the present invention, as long as the power ratio of the signal input and the signal coupling in the embodiment of the present invention can be satisfied. For example, the first MMI may be a 2*3 MMI coupler, the first light pulse is input from one of the two ports on the left end, and the first light pulse is outputted from two of the three ports on the right end. Two beams of light. As long as the two output ports can ensure that the ratio of the power of the first light pulse to the power of the second light pulse is 2:1. The following is an example of an MMI coupler in which the first MMI is 2*2, and the second MMI and the third MMI are 1*3 MMI couplers.

The first MMI 101 can include four ports: port 105, port 106, port 107, and port 108. Port 105 is for receiving a first light pulse. The first light pulse may be generated by a pulse generator or may be generated by a pulse generator generating a light pulse and passing through a device (e.g., MMI) that can split the light pulse. After receiving the first light pulse at port 105, the first MMI splits the first light pulse to obtain a first light pulse and a second light pulse. Wherein, the first beam of light is output from port 106 and transmitted in a clockwise direction of the ring to the second MMI. A second beam of light is output from port 107 and transmitted in a counterclockwise direction along the silicon-based device ring to the third MMI.

It should be understood that the signal input from one end port can only be output from the port at the other end after being processed in the MMI. For example, a first light pulse is input from port 105, and two light pulses obtained after splitting through the first MMI can only be output from the opposite end of port 105, such as from

ports

106, 107, and not from port 108.

It should be understood that the ratio of the power of the first beam of light to the second beam of light may also be 1:2.

The second MMI 102 can be an asymmetric multimode interference coupler, and the second MMI can include four ports: port 109, port 110, port 111, and port 112. Port 111 of the second MMI can be used to receive a first beam of light output from the first MMI, and port 112 is used to output the first beam of light. The port 109 of the second MMI can be used to receive the first OOK optical signal, and the port 110 of the second MMI can be used to receive the second OOK optical signal. The ratio of the power of the first OOK optical signal to the power of the second OOK optical signal is 1:1. The second MMI can be configured to couple the first OOK optical signal, the second OOK optical signal, and the first optical pulse to obtain a first coupled optical signal. The ratio of the power of the first OOK optical signal in the first coupled optical signal to the power of the second OOK optical signal is 2:1. After the first OOK optical signal and the second OOK optical signal pass through the second MMI, the power of the second OOK optical signal is reduced by half.

The second MMI is also used to output a first coupled optical signal from port 112.

The third MMI 103 can be an asymmetric multimode interference coupler, and the third MMI can include four ports: port 113, port 114, port 115, and port 116. Port 115 of the third MMI can be used to receive a second beam of light output from the first MMI, and port 116 is used to output the second beam of light. The port 113 of the third MMI can be used to receive a third OOK optical signal, and the port 114 of the third MMI can be used to receive a fourth OOK optical signal. The ratio of the power of the third OOK optical signal to the power of the fourth OOK optical signal is 1:1. The third MMI can be used to couple the third OOK optical signal, the fourth OOK optical signal, and the second optical pulse to obtain a second coupled optical signal. The ratio of the power of the third OOK optical signal in the second coupled optical signal to the power of the fourth OOK optical signal is 2:1. After the third OOK optical signal and the fourth OOK optical signal pass through the third MMI, the power of the fourth OOK optical signal is reduced by half. The third MMI is also used to output a second coupled optical signal from port 116.

The optical signal modulation pattern conversion method of the embodiment of the invention processes the optical signal in the whole optical domain, and adjusts or couples the power of different optical signals by using the MMI, thereby avoiding using the coupler and the semiconductor optical amplifier to perform different optical signals. Coupling can reduce the complexity of the device structure and simplify the device structure.

It should be understood that the embodiment of the present invention does not limit the order of receiving the OOK optical signal and coupling the OOK optical signal to the second MMI and the third MMI, and the second MMI and the third MMI can also simultaneously receive the two OOKs. The optical signals are coupled. The second MMI and the third MMI are independent of each other and do not interfere with each other.

a first nonlinear silicon-based optical waveguide for receiving a first coupling of a port 112 output of the second MMI The optical signal is also used to receive a second coupled optical signal output by port 116 of the third MMI. Silicon-based optical waveguides have cross-phase modulation effects in third-order nonlinear effects. That is, when the optical signal and the optical pulse in the coupled optical signal simultaneously enter the silicon-based optical waveguide, and the intensity of the optical pulse is 1, the optical signal is cross-phase modulated with the optical pulse, so that the phase of the optical signal changes. Inputting a first coupled optical signal into the first nonlinear silicon-based optical waveguide, and performing cross-phase modulation on the first OOK optical signal, the second OOK optical signal, and the first optical pulse in the first coupled optical signal to obtain a first QPSK optical signal. a second coupled optical signal is further input to the first nonlinear silicon-based optical waveguide, and the third OOK optical signal, the fourth OOK optical signal, and the second optical pulse of the second coupled optical signal are cross-phase modulated to obtain a first Two QPSK optical signals.

The first OOK optical signal, the second OOK optical signal, and the first optical pulse in the first coupled optical signal in the embodiment of the present invention need to arrive at the first nonlinear silicon-based optical waveguide at the same time, and the three can be in the first non- Cross-phase modulation effects occur in linear silicon-based optical waveguides. Similarly, the third OOK optical signal, the fourth OOK optical signal, and the second optical pulse in the second coupled optical signal also arrive at the first nonlinear silicon-based optical waveguide to have a cross-phase modulation effect.

The embodiment of the present invention does not limit how to control the above OOK optical signal and the optical pulse to reach the first nonlinear silicon-based optical waveguide at the same time. For example, a control circuit can be provided outside the device for converting the modulation pattern of the optical signal, the control circuit is used to control the occurrence time of the optical pulse signal, and the output time of the OOK optical signal is controlled to adjust the OOK optical signal and the arrival of the optical pulse. Time in a nonlinear silicon-based optical waveguide to ensure cross-phase modulation effects occur.

The first nonlinear silicon-based optical waveguide may be any one of the following waveguides: a ridge waveguide, a slit waveguide, a slab waveguide, and a photonic crystal waveguide.

In the embodiment of the present invention, a silicon-based optical waveguide (for example, a first nonlinear silicon-based optical waveguide) is used instead of the conventional highly nonlinear optical fiber. Since the silicon-based optical waveguide has a nonlinear effect, the light can be better confined to the micron-sized device, and the effective effective area of the light can be reduced, thereby improving the nonlinearity of the entire device.

In the embodiment of the invention, the entire device can be implemented on a silicon wafer, and each component in the device is a silicon-based device. Due to the small size of silicon-based devices and the compatibility of silicon-based devices with Complementary Metal Oxide Semiconductor (CMOS) processes, this means that silicon-based devices are less expensive to manufacture and easier to implement. Can increase the integration of the entire device. In addition, the efficiency of cross-phase modulation of the optical signal and the optical pulse is proportional to the nonlinearity of the device and the power of the input light. Due to the high nonlinearity of silicon-based optical waveguides, it can occur at low power Cross-phase modulation, which reduces the power loss of the entire device.

The first QPSK optical signal passes through the third MMI to the first MMI, and the second QPSK optical signal passes through the second MMI to the first MMI. The first MMI receives the first QPSK optical signal and the second QPSK optical signal obtained in the first nonlinear silicon-based optical waveguide from the port 107 and the port 106, respectively. The first MMI combines the first QPSK optical signal and the second QPSK optical signal to obtain a first 16-QAM optical signal, and outputs a first 16-QAM optical signal from the port 108.

The multiple ports of the MMI in the embodiment of the present invention are independent of each other, and different ports can independently input different OOK optical signals, and couple different OOK optical signals in the MMI, so that the optical signal transmission scenario with the actual link can be performed. Consistent.

Alternatively, as an embodiment of the invention, the entire device is disposed on a silicon wafer. The MMI in the device is a silicon-based device, and the connection line between the devices is a first silicon-based optical waveguide (ie, a common silicon-based optical waveguide).

The conventional conversion method for realizing the modulation pattern of an optical signal can also process the signal in the field of "optical-electric-optical", and modulate the electrical signal using a Mach-Zehnder modulator to finally generate a 16-QAM optical signal. In the embodiment of the present invention, a silicon-based device is used instead of a highly nonlinear optical fiber, and the signal is processed in the all-optical field to realize conversion of a modulation pattern of the signal, thereby avoiding the use of the conventional "optical-electric-light" to process signals in the electrical field. The rate limit imposed by the time can further increase the signal modulation pattern conversion rate.

The conventional method for converting the modulation pattern of the signal can also adopt the use of a highly nonlinear optical fiber in the all-optical field. In the embodiment of the present invention, a silicon-based device is used, which can avoid the limitation of the conversion rate of the pattern caused by using the SOA device, and further It can reduce the cost and improve the signal modulation pattern conversion rate.

The first 16-QAM optical signal is a single polarization signal. To obtain a polarization-multiplexed 16-QAM optical signal, two 16-QAM optical signals need to be coupled. The following describes how to convert a multi-channel OOK optical signal into a polarization-multiplexed 16-QAM optical signal in conjunction with FIG.

2 is a schematic diagram of a device for converting a modulation pattern of an optical signal according to another embodiment of the present invention. The device of FIG. 2 includes a first MMI 101, a second MMI 102, a third MMI 10, and a first nonlinear silicon-based optical waveguide 104, a fourth MMI 117, a fifth MMI 118, a sixth MMI 119, and a seventh MMI 120. a second nonlinear silicon-based optical waveguide 121 and a two-dimensional photonic crystal grating 122.

The first MMI and the second MMI are connected by a first silicon-based optical waveguide, the first MMI and the third MMI are connected by a first silicon-based optical waveguide, and the first nonlinear silicon-based optical waveguide and the second MMI are first silicon-based optical waveguide a waveguide connection, the first nonlinear silicon-based optical waveguide is connected to the third MMI by the first silicon-based optical waveguide, the first MMI and the fourth MMI are connected by the first silicon-based optical waveguide, and the fourth MMI and the fifth MMI are used first. a silicon-based optical waveguide connection, a fifth MMI and a sixth MMI are connected by a first silicon-based optical waveguide, a fifth MMI and a seventh MMI are connected by a first silicon-based optical waveguide, and a second nonlinear silicon-based optical waveguide and a sixth MMI Connected by the first silicon-based optical waveguide, the second nonlinear silicon-based optical waveguide is connected to the seventh MMI by the first silicon-based optical waveguide, and the first MMI and the two-dimensional photonic crystal grating are connected by the first silicon-based optical waveguide, and the fifth The MMI is connected to the two-dimensional photonic crystal grating using a first silicon-based optical waveguide.

The fourth MMI is configured to receive the light pulse emitted by the pulse generator and split the power of the received light pulse to obtain a first light pulse and a second light pulse.

The first MMI is further configured to synthesize the first QPSK optical signal and the second QPSK optical signal to obtain a first 16-QAM optical signal, and output the first 16-QAM optical signal.

The fifth MMI is for receiving the second light pulse and splitting the second light pulse to obtain a third light pulse and a fourth light pulse.

The sixth MMI is configured to receive the fifth OOK optical signal (OOK5 in FIG. 2), the sixth OOK optical signal (OOK6 in FIG. 2), and the third optical pulse, and the fifth OOK optical signal and the sixth OOK light. The signal is coupled to the third beam of light to obtain a third coupled optical signal.

The seventh MMI is for receiving the seventh OOK optical signal (OOK7 in FIG. 2), the eighth OOK An optical signal (OOK8 in FIG. 2) and a fourth optical pulse are coupled, and the seventh OOK optical signal, the eighth OOK optical signal, and the fourth optical pulse are coupled to obtain a fourth coupled optical signal.

The second nonlinear silicon-based optical waveguide is configured to perform a fifth OOK optical signal (OOK5 in FIG. 2), a sixth OOK optical signal (OOK6 in FIG. 2), and a third optical pulse in the third coupled optical signal. Cross phase modulation yields a third QPSK optical signal (QPSK3 in Figure 2). The second nonlinear silicon-based optical waveguide is further configured to use a seventh OOK optical signal (OOK7 in FIG. 2), an eighth OOK optical signal (OOK8 in FIG. 2), and a fourth optical pulse in the fourth coupled optical signal. Cross-phase modulation is performed to obtain a fourth QPSK optical signal (QPSK4 in Fig. 2).

The third QPSK signal reaches the fifth MMI through the seventh MMI, and the fourth QPSK signal reaches the fifth MMI through the sixth MMI.

The fifth MMI is further configured to combine the third QPSK optical signal and the fourth QPSK optical signal to obtain a second 16-QAM optical signal, and output a second 16-QAM optical signal.

The two-dimensional photonic crystal grating is configured to receive a first 16-QAM optical signal output by the first MMI and a second 16-QAM optical signal output by the fifth MMI, and to the first 16-QAM optical signal and the second 16-QAM light The signals are coupled to obtain a Polarization-division multiplexing (PDM) 16-QAM optical signal.

A device and method for converting a modulation pattern of an optical signal according to an embodiment of the present invention, by splitting an optical pulse using a multimode interference coupler in an all-optical region, coupling two OOK optical signals and one optical pulse, and The use of a silicon-based optical waveguide causes a cross-phase modulation effect of the coupled optical pulse and the two OOK optical signals to generate a QPSK optical signal, and the multi-mode interference coupler can couple the two QPSK optical signals to obtain a 16-QAM optical signal. The two-way 16-QAM optical signal can be coupled by a two-dimensional photonic crystal grating to obtain a PDM-16-QAM optical signal to realize conversion of a modulation pattern of the optical signal, thereby simplifying the device structure and improving the optical signal. The conversion rate of the modulation pattern.

The specific functions and detailed descriptions of the first MMI, the second MMI, the third MMI, and the first nonlinear silicon-based optical waveguide are described in the description of FIG. 1, and details are not described herein again.

The fourth MMI may be a symmetric multimode interference coupler for receiving the light pulses emitted by the pulse generator and splitting the power of the received light pulses to obtain a first light pulse and a second light pulse. Wherein the power of the first light pulse is equal to the power of the second light pulse. The fourth MMI transmits a first optical pulse to the first MMI through the first silicon-based optical waveguide connected between the first MMI and the fourth MMI, and passes through the first silicon-based optical waveguide connected between the fourth MMI and the fifth MMI Five MMI A second light pulse is transmitted.

The fifth MMI may be an asymmetric multimode interference coupler for receiving the second optical pulse, and for splitting the second optical pulse according to the power of the second optical pulse to obtain a third optical pulse and a fourth Beam light pulse. The ratio of the power of the third beam of light to the power of the fourth beam of light is 2:1. It should be understood that the ratio of the power of the third beam of light to the fourth beam of light may also be 1:2.

In an embodiment of the present invention, the fourth MMI may be a 1*2 MMI coupler, and the first MMI and the fifth MMI may be a 2*2 MMI coupler, a second MMI, a third MMI, and a sixth MMI. And the seventh MMI can be a 1*3 MMI coupler.

For a 2*2 MMI coupler, one end of the MMI includes two ports and the other end includes two ports. The 1*3 MMI coupler includes one port at one end and three ports at the other end. Signals input from one end port can only be output from the other end port after being processed in the MMI. However, the present invention does not specifically limit the input and output of the port. For example, the same port can be used as an input port or an output port during different optical signal flow directions.

The fifth MMI can include four ports: port 123, port 124, port 125, and port 126. Port 123 is for receiving a second light pulse. After receiving the second light pulse at port 123, the fifth MMI splits the second light pulse to obtain a third light pulse and a fourth light pulse. The third beam of light is output from port 124 and is transmitted clockwise along the silicon-based device ring to the sixth MMI. The fourth beam of light is output from port 125 and transmitted in a counterclockwise direction along the silicon-based device ring to the seventh MMI.

The sixth MMI 119 can be an asymmetric multimode interference coupler, and the sixth MMI can include four ports: port 127, port 128, port 129, and port 130. The port 129 of the sixth MMI can be used to receive a third beam of light output from the fifth MMI, and the port 130 is for outputting the third beam of light. Port 127 of the sixth MMI can be used to receive the fifth OOK optical signal, and port 128 of the sixth MMI can be used to receive the sixth OOK optical signal. The ratio of the power of the fifth OOK optical signal to the power of the sixth OOK optical signal is 1:1. The sixth MMI can be used to couple the fifth OOK optical signal, the sixth OOK optical signal, and the third optical pulse to obtain a third coupled optical signal. The ratio of the power of the fifth OOK optical signal in the third coupled signal to the power of the sixth OOK optical signal is 2:1. It can be considered that the power of the sixth OOK optical signal is halved after passing through the sixth MMI, and the power of the fifth OOK optical signal is unchanged. The sixth MMI is also used to output a third coupled optical signal from port 130.

The seventh MMI 120 can be an asymmetric multimode interference coupler, and the seventh MMI can include four ports: port 131, port 132, port 133, and port 134. Port 131 of the seventh MMI It may be used to receive a fourth beam of light output from a fifth MMI, and port 134 is for outputting the fourth beam of light. The port 132 of the seventh MMI can be used to receive the seventh OOK optical signal, and the port 133 of the seventh MMI can be used to receive the eighth OOK optical signal. The ratio of the power of the seventh OOK optical signal to the power of the eighth OK optical signal is 1:1. The seventh MMI can be used to couple the seventh OOK optical signal, the eighth OOK optical signal, and the fourth optical pulse to obtain a fourth coupled optical signal. The ratio of the power of the seventh OOK optical signal in the fourth coupled signal to the power of the eighth OK optical signal is 2:1. The seventh MMI is also used to output a fourth coupled optical signal from port 134.

The second nonlinear silicon-based optical waveguide may be made by adding a nonlinear material to the second silicon-based optical waveguide. The Kerr coefficient of the nonlinear material added to the second nonlinear silicon-based optical waveguide is greater than the Kerr coefficient of silicon, and the refractive index of the nonlinear material is smaller than the refractive index of silicon. The second silicon-based optical waveguide may be a conventional silicon-based optical waveguide. The present invention does not limit a specific non-linear material. For example, the nonlinear material may be an organic high molecular polymer or the like.

The fifth OOK optical signal, the sixth OOK optical signal, and the third optical pulse in the third coupled optical signal in the embodiment of the present invention are simultaneously reached in the second nonlinear silicon-based optical waveguide, and the two can be in the second non- Cross-phase modulation effects occur in linear silicon-based optical waveguides. The seventh OOK optical signal, the eighth OOK optical signal, and the fourth optical pulse of the fourth coupled optical signal simultaneously arrive at the second nonlinear silicon-based optical waveguide, and the two can occur in the second nonlinear silicon-based optical waveguide. Cross phase modulation effect. It should be understood that the embodiment of the present invention can ensure the occurrence of the cross-phase modulation effect through the control circuit. For details, refer to FIG. 1 for a detailed description of the cross-phase modulation effect in the first silicon-based optical waveguide, which will not be described in detail herein.

The second nonlinear silicon-based optical waveguide is configured to receive the third beam of light and the third coupled optical signal output by the port 130 of the sixth MMI, and is further configured to receive the fourth beam of light and the output of the port 134 of the third MMI. Four coupled optical signals. The second nonlinear silicon-based optical waveguide has a cross-phase modulation effect in the third-order nonlinear effect. The second nonlinear silicon-based optical waveguide is configured to cross-phase modulate the fifth OOK optical signal, the sixth OOK optical signal, and the third optical pulse of the third coupled optical signal to obtain a third QPSK optical signal (in FIG. 2 QPSK3), and cross-phase-modulating the seventh OOK optical signal, the eighth OOK optical signal, and the fourth optical pulse in the fourth coupled optical signal to obtain a fourth QPSK optical signal (QPSK4 in FIG. 2).

The first nonlinear silicon-based optical waveguide, the first MMI, the second MMI, and the third MMI form a ring structure in the entire device, so that the first QPSK signal generated in the first nonlinear silicon-based optical waveguide can be reached through the third MMI The first MMI, the second QPSK optical signal can reach the first through the second MMI An MMI. The second nonlinear silicon-based optical waveguide, the fifth MMI, the sixth MMI, and the seventh MMI form a ring structure such that the third QPSK optical signal generated in the second nonlinear silicon-based optical waveguide can reach the fifth through the seventh MMI MMI, the fourth QPSK signal can reach the fifth MMI through the six MMI. Therefore, the embodiment of the present invention can form a ring shape by various components, and the structure of the entire device can be simplified.

The first nonlinear silicon-based optical waveguide or the second nonlinear silicon-based optical waveguide may be any one of the following waveguides: a ridge waveguide, a slit waveguide, a slab waveguide, and a photonic crystal waveguide.

In the embodiment of the present invention, a silicon-based optical waveguide (for example, a first nonlinear silicon-based optical waveguide and a second nonlinear silicon-based optical waveguide) is used. Since the silicon-based optical waveguide has a nonlinear effect, the non-linearity of the entire device can be further improved. Linear. In the embodiment of the present invention, the entire device may be disposed on a silicon wafer, and the entire device has seven MMIs, a first nonlinear silicon-based optical waveguide, a second nonlinear silicon-based optical waveguide, and a two-dimensional photonic crystal grating, all of which are silicon-based devices. It can reduce the power loss of the entire device and improve the integration of the entire device.

The fifth MMI is further configured to receive the third QPSK optical signal and the fourth QPSK optical signal obtained in the silicon-based optical waveguide, and synthesize the third QPSK optical signal and the fourth QPSK optical signal to obtain a second 16-QAM optical signal. And outputting a second 16-QAM optical signal from port 126.

The two-dimensional photonic crystal grating can receive the first 16-QAM optical signal output by the first MMI from port 108 and receive the second 16-QAM optical signal output by the fifth MMI from port 126. The two-dimensional photonic crystal grating is further configured to synthesize the first 16-QAM optical signal and the second 16-QAM optical signal to obtain a PDM-16-QAM optical signal, and output the PDM-16-QAM optical signal.

The left loop in the device of the embodiment of the present invention includes: a first MMI, a second MMI, a third MMI, and a first nonlinear silicon-based optical waveguide, and the right loop includes: a fifth MMI, a sixth MMI, and a seventh MMI and a second nonlinear silicon-based optical waveguide. The left and right sides of each device are symmetrically distributed, so that the first 16-QAM signal and the second 16-QAM signal can be generated as synchronously as possible, so that the two are coupled in the two-dimensional photonic crystal grating, so that the coupling can be improved to obtain polarization-multiplexed PDM. -16-QAM optical signal efficiency.

Alternatively, as an embodiment of the invention, the device is disposed on a silicon wafer. All components in the device are silicon-based devices, and the connection lines between the devices are the first silicon-based optical waveguides, that is, the connection lines between the devices are ordinary silicon-based waveguide lines.

The source of the OOK optical signal is not limited in the embodiment of the present invention. It is assumed that the device in the embodiment of the present invention is disposed at the first network node. a first OOK optical signal, a second OOK optical signal, a third OOK optical signal, a fourth OOK optical signal, a fifth OOK optical signal, a sixth OOK optical signal, and a seventh The OOK optical signal and the eighth OK optical signal may be generated by an electrical signal modulation of the first network node, or may be generated by the second network node and transmitted by the second network node to the first network node. The second network node can be different from the first network node.

Since the processing of silicon-based devices can be compatible with CMOS processes, this means that silicon-based devices are relatively inexpensive to manufacture and easy to implement. Traditional signal modulation patterns are converted using discrete nonlinear optics such as nonlinear fiber, SOA, and the like. In the embodiment of the present invention, the entire device can be disposed on a silicon chip, and the components in the device are all silicon-based devices, and the connection lines between the devices are all first silicon-based optical waveguides, and the entire device uses an integrated silicon-based device. This reduces device cost, increases device integration, and simplifies device structure.

A device for converting a modulation pattern of a signal according to an embodiment of the present invention is described in detail above with reference to FIGS. 1 and 2. A method of converting a modulation pattern of a signal according to an embodiment of the present invention will be described in detail below with reference to FIGS. 3 and 4.

3 is a schematic flow chart of a method of converting a modulation pattern of a signal according to an embodiment of the present invention.

301. The first MMI receives the first optical pulse, and splits the first optical pulse to obtain a first optical pulse and a second optical pulse.

302. The second MMI receives the first OOK optical signal, the second OOK optical signal, and the first optical pulse, and couples the first OOK optical signal, the second OOK optical signal, and the first optical pulse to obtain a first coupling. Optical signal.

303. The third MMI receives the third OOK optical signal, the fourth OOK optical signal, and the second optical pulse, and couples the third OOK optical signal, the fourth OOK optical signal, and the second optical pulse to obtain a second coupling. Optical signal.

304. The first nonlinear silicon-based optical waveguide cross-phase-modulates the first OOK optical signal, the second OOK optical signal, and the first optical pulse of the first coupled optical signal to obtain a first QPSK optical signal.

305. The first nonlinear silicon-based optical waveguide cross-phase-modulates the third OOK optical signal, the fourth OOK optical signal, and the second optical pulse of the second coupled optical signal to obtain a second QPSK optical signal.

306. The first QPSK optical signal reaches the first MMI through the third MMI, and the second QPSK optical signal reaches the first MMI through the second MMI.

307. The first MMI synthesizes the first QPSK optical signal and the second QPSK optical signal. To the first 16-QAM optical signal.

308. The first MMI outputs the first 16-QAM optical signal.

A device and method for converting a modulation pattern of an optical signal according to an embodiment of the present invention, by splitting an optical pulse using a multimode interference coupler in an all-optical region, coupling two OOK optical signals and one optical pulse, and The use of a silicon-based optical waveguide causes a cross-phase modulation effect of the coupled optical pulse and the two OOK optical signals to generate a QPSK optical signal, and the multi-mode interference coupler can couple the two QPSK optical signals to obtain a 16-QAM optical signal. In order to realize the conversion of the modulation pattern of the optical signal, the rate of conversion of the modulation pattern of the optical signal can be improved.

The corresponding flow of the method for converting the modulation pattern of the device in the embodiment of FIG. 3 may be performed by the respective components in the device of FIG. 1 of the foregoing embodiment of the present invention. For brevity, no further details are provided herein.

401. The fourth MMI receives the light pulse emitted by the pulse generator, and splits the received light pulse according to the power to obtain the first light pulse and the second light pulse.

402. The first MMI receives the first light pulse, and splits the first light pulse to obtain a first light pulse and a second light pulse.

403. The second MMI receives the first OOK optical signal, the second OOK optical signal, and the first optical pulse, and couples the first OOK optical signal, the second OOK optical signal, and the first optical pulse to obtain a first coupling. Optical signal.

404. The third MMI receives the third OOK optical signal, the fourth OOK optical signal, and the second optical pulse, and couples the third OOK optical signal, the fourth OOK optical signal, and the second optical pulse to obtain a second coupling. Optical signal.

405. The first nonlinear silicon-based optical waveguide cross-phase-modulates the first OOK optical signal, the second OOK optical signal, and the first optical pulse of the first coupled optical signal to obtain a first QPSK optical signal.

406. The first nonlinear silicon-based optical waveguide cross-phase-modulates the third OOK optical signal, the fourth OOK optical signal, and the second optical pulse of the second coupled optical signal to obtain a second QPSK optical signal.

407. The first QPSK optical signal reaches the first MMI through the third MMI, and the second QPSK optical signal reaches the first MMI through the second MMI.

408. The first MMI synthesizes the first QPSK optical signal and the second QPSK optical signal. To the first 16-QAM optical signal.

409. The first MMI outputs the first 16-QAM optical signal.

410. The fifth MMI receives the second optical pulse and splits the second optical pulse to obtain a third optical pulse and a fourth optical pulse.

411. The sixth MMI receives the fifth OOK optical signal, the sixth OOK optical signal, and the third optical pulse, and couples the fifth OOK optical signal, the sixth OOK optical signal, and the third optical pulse to obtain a third coupled light. signal.

412. The seventh MMI receives the seventh OOK optical signal, the eighth OOK optical signal, and the fourth optical pulse, and couples the seventh OOK optical signal, the eighth OOK optical signal, and the fourth optical pulse to obtain a fourth coupled light. signal.

413. The second nonlinear silicon-based optical waveguide cross-phase-modulates the fifth OOK optical signal, the sixth OOK optical signal, and the third optical pulse of the third coupled optical signal to obtain a third QPSK optical signal.

414. The second nonlinear silicon-based optical waveguide cross-phase-modulates the seventh OOK optical signal, the eighth OOK optical signal, and the fourth optical pulse of the fourth coupled optical signal to obtain a fourth QPSK optical signal.

415. The third QPSK optical signal reaches the fifth MMI through the seventh MMI, and the fourth QPSK optical signal reaches the fifth MMI through the sixth MMI.

416. The fifth MMI combines the third QPSK optical signal and the fourth QPSK optical signal to obtain a second 16-QAM signal.

417. The fifth MMI outputs the second 16-QAM optical signal.

418. The two-dimensional photonic crystal grating receives the first 16-QAM optical signal and the second 16-QAM optical signal, and couples the first 16-QAM optical signal and the second 16-QAM optical signal to obtain PDM-16-QAM. Optical signal.

A device and method for converting a modulation pattern of an optical signal according to an embodiment of the present invention, by splitting an optical pulse using a multimode interference coupler in an all-optical region, coupling an OOK optical signal and a pulsed light, and using silicon-based light The waveguide causes a cross-phase modulation effect between the coupled optical pulse and the OOK optical signal to generate a QPSK optical signal. The multi-mode interference coupler can couple the two QPSK optical signals to obtain a 16-QAM optical signal, and pass the two-dimensional photonic crystal grating. The two 16-QAM optical signals can be coupled to obtain a PDM-16-QAM optical signal to realize conversion of a modulation pattern of the optical signal, thereby simplifying the device structure and improving the conversion rate of the modulation pattern of the optical signal. .

The corresponding flow of the method for converting the modulation pattern of the optical signal in the embodiment of FIG. 4 may be performed by the various components in the device of FIG. 2 of the foregoing embodiment of the present invention. For brevity, no further details are provided herein.

It is to be understood that the specific examples of the invention are intended to be illustrative of the embodiments of the invention.

The phrase "one embodiment" or "an embodiment" as used throughout the specification means that a particular feature, structure, or characteristic relating to an embodiment is included in at least one embodiment of the invention. Thus, "in one embodiment" or "in an embodiment" or "an" In addition, these particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

It should be understood that, in various embodiments of the present invention, the size of the sequence numbers of the above processes does not mean the order of execution, and the order of execution of each process should be determined by its function and internal logic, and should not be taken to the embodiments of the present invention. The implementation process constitutes any limitation.

It should be understood that in the embodiment of the present invention, "B corresponding to A" means that B is associated with A, and B can be determined according to A. However, it should also be understood that determining B from A does not mean that B is only determined based on A, and that B can also be determined based on A and/or other information.

Those of ordinary skill in the art will appreciate that the elements and algorithm steps of the various examples described in connection with the embodiments disclosed herein can be implemented in electronic hardware or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the solution. A person skilled in the art can use different methods for implementing the described functions for each particular application, but such implementation should not be considered to be beyond the scope of the present invention.

A person skilled in the art can clearly understand that for the convenience and brevity of the description, the specific process of the foregoing method may refer to the response description in the foregoing system embodiment, and details are not described herein again.

In the several embodiments provided by the present application, it should be understood that the disclosed systems, devices, and methods may be implemented in other manners. For example, the device embodiments described above are merely illustrative. For example, the division of the unit is only a logical function division. In actual implementation, there may be another division manner, for example, multiple units or components may be combined or Can be integrated into another system, or some features can be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection through some interface, device or unit, and may be in an electrical, mechanical or other form.

The units described as separate components may or may not be physically separate. The components displayed for the unit may or may not be physical units, ie may be located in one place, or may be distributed over multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

The functions may be stored in a computer readable storage medium if implemented in the form of a software functional unit and sold or used as a standalone product. Based on such understanding, the technical solution of the present invention, which is essential or contributes to the prior art, or a part of the technical solution, may be embodied in the form of a software product, which is stored in a storage medium, including The instructions are used to cause a computer device (which may be a personal computer, server, or network device, etc.) to perform all or part of the steps of the methods described in various embodiments of the present invention. The foregoing storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk, and the like. .

The above is only a specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily think of changes or substitutions within the technical scope of the present invention. It should be covered by the scope of the present invention. Therefore, the scope of the invention should be determined by the scope of the appended claims.

Claims

A device for converting a modulation pattern of an optical signal, comprising:

a first nonlinear silicon-based optical waveguide, a first multimode interference optical coupler MMI, a second MMI, and a third MMI;

The first MMI and the second MMI are connected by a first silicon-based optical waveguide, and the first MMI and the third MMI are connected by a first silicon-based optical waveguide, the first nonlinear silicon-based optical waveguide The second MMI is connected by a first silicon-based optical waveguide, and the first nonlinear silicon-based optical waveguide is connected to the third MMI by a first silicon-based optical waveguide;

The first MMI is configured to receive a first optical pulse, and split the first optical pulse to obtain a first beam of light and a second beam of light;

The second MMI is configured to receive a first OOK optical signal, a second OOK optical signal, and a first optical pulse, and to the first OOK optical signal, the second OOK optical signal, and the first beam Pulses are coupled to obtain a first coupled optical signal;

The third MMI is configured to receive a third OOK optical signal, a fourth OOK optical signal, and the second optical pulse, and to the third OOK optical signal, the fourth OOK optical signal, and the second Beam light pulses are coupled to obtain a second coupled optical signal;

The first nonlinear silicon-based optical waveguide is configured to perform cross-phase modulation on the first OOK optical signal, the second OOK optical signal, and the first optical pulse in the first coupled optical signal, Obtaining a first quadrature phase shift keying QPSK optical signal, wherein the first nonlinear silicon based optical waveguide is further configured to use the third OOK optical signal and the fourth OOK light in the second coupled optical signal Performing cross-phase modulation on the signal and the second beam of light to obtain a second QPSK optical signal;

The first QPSK optical signal reaches the first MMI through the third MMI, and the second QPSK optical signal reaches the first MMI through the second MMI;

The first MMI is further configured to synthesize the first QPSK optical signal and the second QPSK optical signal to obtain a first 16-quadrature amplitude modulated QAM optical signal, and output the first 16-QAM light. signal.
The device of claim 1 wherein

The first MMI is specifically configured to split the first optical pulse according to the power of the first optical pulse, wherein a power of the first optical pulse and a power of the second optical pulse The ratio is 2:1;

The ratio of the power of the first OOK optical signal to the power of the second OOK optical signal in the first coupled optical signal is 2:1;

The ratio of the power of the third OOK optical signal to the power of the fourth OOK optical signal in the second coupled optical signal is 2:1.
The device according to claim 1 or 2, wherein the device further comprises: a fourth MMI, a fifth MMI, a sixth MMI, a seventh MMI, a second nonlinear silicon-based optical waveguide, and a two-dimensional photonic crystal Grating

The first MMI and the fourth MMI are connected by a first silicon-based optical waveguide, the fourth MMI and the fifth MMI are connected by a first silicon-based optical waveguide, the fifth MMI and the sixth The MMI is connected by a first silicon-based optical waveguide, the fifth MMI is connected to the seventh MMI by a first silicon-based optical waveguide, and the second nonlinear silicon-based optical waveguide and the sixth silicon for the sixth MMI a second optical silicon-based optical waveguide connected to the seventh MMI by a first silicon-based optical waveguide, the first MMI and the first silicon-based optical waveguide for the two-dimensional photonic crystal grating Connecting, the fifth MMI and the two-dimensional photonic crystal grating are connected by a first silicon-based optical waveguide;

The fourth MMI is configured to receive a light pulse emitted by the pulse generator, and split the received power of the light pulse to obtain the first light pulse and the second light pulse;

The fifth MMI is configured to receive a second optical pulse, and split the second optical pulse to obtain a third optical pulse and a fourth optical pulse;

The sixth MMI is configured to receive a fifth OOK optical signal, a sixth OOK optical signal, and a third optical pulse, and to the fifth OOK optical signal, the sixth OOK optical signal, and the third beam Pulses are coupled to obtain a third coupled optical signal;

The seventh MMI is configured to receive a seventh OOK optical signal, an eighth OOK optical signal, and a fourth optical pulse, and to the seventh OOK optical signal, the eighth OOK optical signal, and the fourth beam The pulses are coupled to obtain a fourth coupled optical signal;

The second nonlinear silicon-based optical waveguide is configured to cross-phase modulate the fifth OOK optical signal, the sixth OOK optical signal, and the third optical pulse in the third coupled optical signal, Obtaining a third QPSK optical signal, wherein the second nonlinear silicon-based optical waveguide is further configured to: the seventh OOK optical signal, the eighth OOK optical signal, and the fourth of the fourth coupled optical signal The beam of light pulses is cross-phase modulated to obtain a fourth QPSK optical signal;

The third QPSK optical signal reaches the fifth MMI through the seventh MMI, and the fourth QPSK optical signal reaches the fifth MMI through the sixth MMI;

The fifth MMI is further configured to synthesize the third QPSK optical signal and the fourth QPSK optical signal to obtain a second 16-QAM optical signal, and output the second 16-QAM optical signal;

The two-dimensional photonic crystal grating is configured to receive a first 16-QAM optical signal output by the first MMI and a second 16-QAM optical signal output by the fifth MMI, and to the first 16-QAM light The signal is coupled to the second 16-QAM optical signal to obtain a polarization multiplexed PDM-16-QAM optical signal.
The device according to claim 3, wherein said first MMI, said second MMI, said third MMI, said fifth MMI, said sixth MMI, and said seventh MMI are non- A symmetric MMI, the fourth MMI being a symmetric MMI.
A device according to claim 3 or 4, wherein

The ratio of the power of the first light pulse to the power of the second light pulse is 1:1;

The fifth MMI is specifically configured to split the second optical pulse according to the power of the second optical pulse, wherein a power of the third optical pulse and a power of the fourth optical pulse The ratio is 2:1;

The ratio of the power of the fifth OOK optical signal to the power of the sixth OOK optical signal in the third coupled optical signal is 2:1;

The ratio of the power of the seventh OOK optical signal to the power of the eighth OOK optical signal in the fourth coupled optical signal is 2:1.
The device according to any one of claims 3 to 5, wherein the fourth MMI is a 1*2 MMI coupler, and the first MMI and the fifth MMI are 2*2 MMI The coupler, the second MMI, the third MMI, the sixth MMI, and the seventh MMI are 1*3 MMI couplers.
The device according to any one of claims 3 to 6, wherein the first nonlinear silicon-based optical waveguide and the second nonlinear silicon-based optical waveguide have a cross-phase modulation effect.
The device according to any one of claims 3 to 7, wherein the first nonlinear silicon-based optical waveguide or the second nonlinear silicon-based optical waveguide is one of the following waveguides: a ridge waveguide , slot waveguides, slab waveguides, and photonic crystal waveguides.
A device according to any one of claims 3 to 8, the device being arranged at a first network node, characterized in that

The first OOK optical signal, the second OOK optical signal, the third OOK optical signal, the fourth OOK optical signal, the fifth OOK optical signal, the sixth OOK optical signal, Generating a seventh OOK optical signal and the eighth OK optical signal by an electrical signal of the first network node; or

The first OOK optical signal, the second OOK optical signal, the third OOK optical signal, the fourth OOK optical signal, the fifth OOK optical signal, the sixth OOK optical signal, the The seventh OOK optical signal and the eighth OK optical signal are generated by the second network node and transmitted by the second network node to the first network node.
A device according to any one of claims 1 to 9, wherein the device is disposed on a silicon wafer.
A method for converting a modulation pattern of an optical signal, the method being used for a device for optical signal modulation pattern conversion, the device comprising a first nonlinear silicon-based optical waveguide, a first multimode interference optical coupler MMI, a second MMI and a third MMI, wherein the first MMI and the second MMI are connected by a first silicon-based optical waveguide, and the first MMI and the third MMI are connected by a first silicon-based optical waveguide, the A nonlinear silicon-based optical waveguide is coupled to the second MMI by a first silicon-based optical waveguide, and the first nonlinear silicon-based optical waveguide is coupled to the third MMI by a first silicon-based optical waveguide, wherein , the method includes:

Receiving, by the first MMI, a first light pulse, and splitting the first light pulse to obtain a first light pulse and a second light pulse;

The second MMI receives the first OOK optical signal, the second OOK optical signal, and the first optical pulse, and the first OOK optical signal, the second OOK optical signal, and the first beam Pulses are coupled to obtain a first coupled optical signal;

The third MMI receives a third OOK optical signal, a fourth OOK optical signal, and the second optical pulse, and the third OOK optical signal, the fourth OOK optical signal, and the second beam Pulses are coupled to obtain a second coupled optical signal;

The first nonlinear silicon-based optical waveguide cross-phase-modulates the first OOK optical signal, the second OOK optical signal, and the first optical pulse in the first coupled optical signal to obtain a first a quadrature phase shift keying QPSK optical signal;

The first nonlinear silicon-based optical waveguide cross-phase-modulates the third OOK optical signal, the fourth OOK optical signal, and the second optical pulse in the second coupled optical signal to obtain a first Two QPSK optical signals;

The first QPSK optical signal reaches the first MMI through the third MMI, and the second QPSK optical signal reaches the first MMI through the second MMI;

The first MMI synthesizes the first QPSK optical signal and the second QPSK optical signal to obtain a first 16-quadrature amplitude modulated QAM optical signal;

The first MMI outputs the first 16-QAM optical signal.
The method of claim 11 wherein said splitting said first optical pulse by said first MMI comprises:

The first MMI splits the first optical pulse according to a power of the first optical pulse;

among them,

The ratio of the power of the first beam of light pulses to the power of the second beam of light pulses is 2:1;

The ratio of the power of the first OOK optical signal to the power of the second OOK optical signal in the first coupled optical signal is 2:1;

The ratio of the power of the third OOK optical signal to the power of the fourth OOK optical signal in the second coupled optical signal is 2:1.
The method according to claim 11 or 12, wherein when said device further comprises: a fourth MMI, a fifth MMI, a sixth MMI, a seventh MMI, a second nonlinear silicon-based optical waveguide, and two-dimensional photons In the case of a crystal grating, the method further includes:

The fourth MMI receives the light pulse emitted by the pulse generator, and splits the received light pulse according to the power to obtain the first light pulse and the second light pulse;

The fifth MMI receives the second light pulse, and splits the second light pulse to obtain a third light pulse and a fourth light pulse;

The sixth MMI receives a fifth OOK optical signal, a sixth OOK optical signal, and the third optical pulse, and the fifth OOK optical signal, the sixth OOK optical signal, and the third beam Pulses are coupled to obtain a third coupled optical signal;

The seventh MMI receives the seventh OOK optical signal, the eighth OOK optical signal, and the fourth optical pulse, and the seventh OOK optical signal, the eighth OOK optical signal, and the fourth beam The pulses are coupled to obtain a fourth coupled optical signal;

The second nonlinear silicon-based optical waveguide performs cross-phase modulation on the fifth OOK optical signal, the sixth OOK optical signal, and the third optical pulse in the third coupled optical signal to obtain a first Three QPSK optical signals;

The second nonlinear silicon-based optical waveguide cross-phase-modulates the seventh OOK optical signal, the eighth OOK optical signal, and the fourth optical pulse of the fourth coupled optical signal. To the fourth QPSK optical signal;

The third QPSK optical signal reaches the fifth MMI through the seventh MMI, and the fourth QPSK optical signal reaches the fifth MMI through the sixth MMI;

The fifth MMI synthesizes the third QPSK optical signal and the fourth QPSK optical signal to obtain a second 16-QAM optical signal;

The fifth MMI outputs the second 16-QAM optical signal;

The two-dimensional photonic crystal grating receives a first 16-QAM optical signal output by the first MMI and a second 16-QAM optical signal output by the fifth MMI, and the first 16-QAM optical signal and The second 16-QAM optical signal is coupled to obtain a polarization multiplexed PDM-16-QAM optical signal.
The method of claim 13 wherein:

The ratio of the power of the first light pulse to the power of the second light pulse is 1:1;

The fifth MMI is further configured to split the second optical pulse, comprising splitting the second optical pulse according to a power of the second optical pulse, wherein a power of the third optical pulse The ratio of the power of the fourth beam of light pulses is 2:1;

The ratio of the power of the fifth OOK optical signal to the power of the sixth OOK optical signal in the third coupled optical signal is 2:1;

The ratio of the power of the seventh OOK optical signal to the power of the eighth OOK optical signal in the fourth coupled optical signal is 2:1.