CN101989024B - Method and device for transmitting optical signals - Google Patents

Abstract

Embodiments of the present invention provide an optical signal transmission method and device. The method includes: forward multiplexing the received signal light and the pump light generated by the laser to generate forward multiplexed light, performing quasi-phase matching on the forward multiplexed light, and generating a signal including TM mode conversion idler light and TE mode Forward beam of light; decompose the forward beam into pump light, TE mode signal light and TM mode converted idler light; convert TE mode signal light into TM mode signal light, and convert TM mode converted idler light into TE Mode-converted idler light; demultiplex pump light, TM mode signal light and TE mode-converted idler light to generate inverse multiplexed light, perform quasi-phase matching on inverse multiplexed light, and generate idler light including TM mode conversion frequency light and the reverse beam of TE mode-converted idler light; decompose the reverse beam into pump light, TE mode-converted idler light and TM mode-converted idler light. The technical scheme has the advantages of stable system and simple optical path structure.

Description

Optical signal transmission method and device

technical field

The invention relates to optical communication technology, in particular to an optical signal transmission method and device.

Background technique

In the field of optical signal transmission, all-optical wavelength conversion technology is to realize the conversion of information from one wavelength to another wavelength or multiple wavelengths in the optical domain. Commonly used all-optical wavelength conversion technologies mainly include: cross-gain modulation (XGM, Cross-gain modulation), cross-phase modulation (XPM, Cross-phase modulation), nonlinear optical ring cavity (NOLM, Nonlinear optical loop mirror), laser gain saturation effect, four-wave mixing (FWM, Four-wave mixing), second-order nonlinear effects, etc. Among these schemes, the wavelength conversion technology based on the second-order nonlinear effect of the periodically polarized lithium niobate (PPLN, Periodically Poled LiNbO ₃ Waveguide) optical waveguide has its unique advantages, such as fast response speed and strict The signal optical rate and modulation form are completely transparent, the unique multi-wavelength simultaneous conversion capability, and the extremely low noise index in the conversion process have attracted more and more attention from researchers at home and abroad in recent years.

FIG. 1 is a schematic diagram of an optical signal transmission device provided by the first prior art. The signal light enters the device through the first optical coupler 4 , is amplified by the amplifier 3 , and its polarization state is adjusted by the polarization controller 5 , and then enters the PPLN optical waveguide 1 . The optical isolator 6 ensures the unidirectional transmission of light in the clockwise direction in the ring cavity, and the second coupler 7 couples the light beam. The pump light is generated by a ring cavity laser containing a PPLN optical waveguide. A wavelength selector 2 consisting of an attenuator 8 and a filter 9 determines the wavelength of the pump light. The pump light generated by the lasing realizes the sum-frequency effect in the PPLN to generate sum-frequency light. A difference frequency effect occurs between the sum frequency light and the signal light to generate converted idler light.

Existing technology 1 has the following defects: the PPLN optical waveguide in this device is made by annealing proton exchange method, which only allows transmission of TM mode, and all light must be converted to TM mode by a polarization controller, and the input signal light loses TE mode . Therefore, the output converted idler light is related to the polarization of the input signal light, the performance of the system is low, and the conversion efficiency is not high.

FIG. 2 is a schematic diagram of an optical signal transmission device provided by the second prior art. The optical waveguide 2 in this device is coated with a film with high reflection to 0.77 μm band and high transmission to 1.55 μm band on the front surface, and coated with a film with high transmission to both 0.77 μm and 1.55 μm on the rear end surface. The signal light is input into the PPLN optical waveguide 2 through the circulator 1, the pump light is reversely pumped in TM mode, and the signal light is orthogonally decomposed into TM mode and TE mode. The TM mode of the pump light reflected by the front face satisfies the quasi-phase matching condition of the difference frequency, and the difference frequency generates the wavelength-converted idler light of the TM mode. The signal light, pump light and converted idler light are output through the lens 3, pass through the quarter-wave plate 4, only act on the light in the 1.55μm band, and then pass through the mirror 5, which has high transmission to the 0.77μm band 1. Highly reflective to the 1.55 μm band, so the signal light and converted idler light in the 1.55 μm band pass through the quarter-wave plate 4 twice, and the polarization state is rotated by 90°, and the TM mode of the signal light is converted to the TE mode , TE mode is converted to TM mode. The TM mode generated during forward transmission converts idler light into TE mode, while in reverse transmission, the TM mode of signal light (originally TE mode) and the reverse pumped pump light TM mode meet quasi-phase matching Conditions, the difference frequency generates wavelength-converted idler light in TM mode, and the converted idler light with both TM mode and TE mode is output through the circulator to realize the wavelength conversion function.

The second prior art has the following defects: the device uses a series of optical devices such as lenses, wave plates, and mirrors, and it is difficult to construct a spatial optical path. The stability of the system is greatly affected by the external environment, and the practicability is not strong; The device requires the injection of an additional pump light source, which increases the cost; the device uses the PPLN optical waveguide prepared by the liquid phase epitaxy method. Although the TE and TM modes can be transmitted at the same time, the optical waveguide prepared by the liquid phase epitaxy method is not large. Conversion efficiency is subject to certain limitations.

Contents of the invention

In order to overcome the defects in the prior art, an embodiment of the present invention proposes an optical signal transmission method and device, which are used to solve the problems in the prior art of difficulty in constructing an optical path, poor system stability, and low conversion efficiency.

On the one hand, an embodiment of the present invention provides a method for transmitting an optical signal, the method comprising:

The pump light generated by the lasing is forward-multiplexed with the received signal light to generate forward multiplexed light, and the forward multiplexed light is quasi-phase-matched to generate idler light and TE mode including TM mode conversion Forward beam of signal light;

Decomposing the forward light beam comprising TM mode conversion idler light and TE mode signal light into pump light, TE mode signal light and TM mode conversion idler light;

Converting the TE mode signal light into a TM mode signal light, and converting the TM mode converted idler light into a TE mode converted idler light;

Inversely multiplexing the pump light, TM mode signal light, and TE mode converted idler light to generate inverse multiplexed light, and performing quasi-phase matching on the inversely multiplexed light to generate an idler including TM mode conversion Frequency light and TE mode to convert the reverse beam of idler light;

Decomposing the reverse light beams of the TM mode conversion idler light and the TE mode conversion idler light into pumping light, TE mode conversion idler light and TM mode conversion idler light.

On the other hand, an embodiment of the present invention also provides an optical signal transmission device, the device comprising:

The first multiplexing and demultiplexing unit is used to forward multiplex the pump light generated by the laser and the received signal light to generate forward multiplexed light;

A matching unit, configured to perform quasi-phase matching on the forward multiplexed light, to generate a forward beam comprising TM mode converted idler light and TE mode signal light;

The second multiplexing and demultiplexing unit is used to decompose the forward beam comprising TM mode conversion idler light and TE mode signal light into pump light, TE mode signal light and TM mode conversion idler light;

an optical rotation unit, configured to convert the TE mode signal light into a TM mode signal light, and convert the TM mode converted idler light into a TE mode converted idler light;

The second multiplexing and demultiplexing unit is also used to inversely multiplex the pump light, TM mode signal light and TE mode converted idler light to generate inverse multiplexed light;

The matching unit is further used to perform quasi-phase matching on the inverse multiplexed light, and generate a reverse beam including TM mode-converted idler light and TE mode-converted idler light;

The first multiplexing and demultiplexing unit is also used to decompose the reverse light beam comprising TM mode conversion idler light and TE mode conversion idler light into pump light, TE mode conversion idler light and TM mode conversion Idle light.

The beneficial effect of the embodiment of the present invention is that the automatic synchronization of the TE mode and the TM mode of the light is realized through optical rotation; it has the advantages of stable system, simple optical path structure and high conversion efficiency.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. For those skilled in the art, other drawings can also be obtained according to these drawings without any creative effort.

FIG. 1 is a schematic diagram of an optical signal transmission device provided by prior art 1;

FIG. 2 is a schematic diagram of an optical signal transmission device provided by prior art 2;

FIG. 3 is a flowchart of an optical signal transmission method provided by Embodiment 1 of the present invention;

4 is a schematic diagram of quasi-phase matching between the pump light and the optical signal based on the difference frequency second-order nonlinear effect provided by Embodiment 1 of the present invention;

5 is a schematic diagram of quasi-phase matching between the pump light and the optical signal based on the second-order nonlinear effect of cascaded frequency multiplication and difference frequency provided by Embodiment 1 of the present invention;

6 is a schematic diagram of quasi-phase matching between the pump light and the optical signal based on the second-order cascaded nonlinear effect of the cascaded sum frequency and difference frequency provided by Embodiment 1 of the present invention;

FIG. 7 is a flowchart of an optical signal transmission method provided in Embodiment 1 of the present invention;

FIG. 8 is a schematic diagram of an optical signal transmission device provided in Embodiment 2 of the present invention;

FIG. 9 is a direct bonded PPLN optical waveguide provided by Embodiment 2 of the present invention;

FIG. 10 is a schematic diagram of an optical signal transmission device provided in Embodiment 3 of the present invention;

FIG. 11 is a schematic diagram of an optical signal transmission device provided in Embodiment 4 of the present invention;

FIG. 12 is a schematic structural diagram of an optical signal transmission device provided in Embodiment 4 of the present invention;

FIG. 13 is a schematic structural diagram of a first multiplexing and demultiplexing device provided in Embodiment 4 of the present invention;

FIG. 14 is a schematic structural diagram of a second multiplexing and demultiplexing device provided in Embodiment 4 of the present invention;

FIG. 15 is a schematic structural diagram of a single wavelength selector provided in Embodiment 4 of the present invention;

FIG. 16 is a schematic structural diagram of a first multiplexing and demultiplexing device provided in Embodiment 5 of the present invention;

FIG. 17 is a schematic structural diagram of a second multiplexing and demultiplexing device provided in Embodiment 5 of the present invention;

FIG. 18 is a schematic structural diagram of a dual-wavelength selector provided in Embodiment 5 of the present invention.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

Embodiment one

An embodiment of the present invention provides a method for transmitting an optical signal, which will be described in detail below with reference to the accompanying drawings.

FIG. 3 is a flowchart of an optical signal transmission method provided by an embodiment of the present invention. The methods include:

S301: Perform forward multiplexing on the received signal light and the pump light generated by the laser to generate forward multiplexed light, perform quasi-phase matching on the forward (counterclockwise) multiplexed light, and generate TM mode conversion Forward beam of idler light and TE mode signal light;

In this embodiment, the pump light is generated when the resonance condition for generating pump light by lasing is satisfied.

In this embodiment, before step S301, it further includes: adjusting the polarization state of the pump light to output in TM mode.

In this embodiment, the quasi-phase matching of the pump light generated by the lasing with the signal light received from the outside refers to: periodically modulating the signal light along the propagation direction of the pump light; the quasi-phase matching technology makes The wave vector mismatch caused by the different propagation constants of the interacting light waves is periodically corrected and compensated, so that the new light field generated by the nonlinear effect can be effectively superimposed and continuously strengthened, and a TM mode conversion idler light and TE mode signal light are generated. forward beam.

FIG. 4 is a schematic diagram of quasi-phase matching between the pump light and the optical signal based on the second-order nonlinear effect of difference frequency generation (DFG). Among them, the pump light and the signal light are input into the PPLN optical waveguide at the same time, and the pump light and the signal light meet the quasi-phase matching condition (Quasi-phaseMatch, QPM), and the nonlinear interaction based on the difference frequency occurs in the PPLN optical waveguide, resulting in For the converted idler light, in the general case of ω _i =ω _p -ω _s , the pump light is located in the 0.77 μm band, and the signal light and converted idler light are located in the 1.55 μm band. According to the principle of energy conservation, the wavelengths of pump light, signal light and converted idler light satisfy the following relationship:

DFG: 1/λ _i =1/λ _p −1/λ _s .

Among them, λ _i is the wavelength of converted idler light, λ _p is the wavelength of pump light, and λ _s is the wavelength of signal light; ω is the frequency axis, ω _i is the frequency of converted idler light, and ω _p is the frequency of pump light , ω _s is the frequency of the signal light.

FIG. 5 is a schematic diagram of quasi-phase matching between the pump light and the optical signal based on the second-order nonlinear effect of cascaded harmonic and difference-frequency generation (cascaded harmonic and difference-frequency generation, SHG+DFG). Among them, two waves of pumping light and signal light are input into the PPLN optical waveguide at the same time, the pumping light is located at the QPM wavelength of the cascaded frequency doubling, and the cascading frequency doubling effect occurs to generate the frequency doubling light, ω _SH = 2ω _p frequency doubling light The DFG interaction with the signal light generates converted idler light. In the usual case of ω _i = ω _SH -ω _s , the signal light, pump light and converted idler light are located in the 1.5 μm band, and the doubled frequency light is located in the 0.77 μm band . According to the principle of energy conservation, the wavelengths of pump, signal light, frequency doubled light, and converted idler light satisfy the following relationship:

SHG: 1/λ _SH = 2/λ _p ;

DFG: 1/λ _i =1/λ _SH −1/λ _s .

Among them, λ _SH is the frequency doubled light wavelength, λ _p is the pump light wavelength, λ _S is the signal light wavelength, λ _i is the converted idler light wavelength; ω is the frequency coordinate axis, ω _SH is the frequency of the frequency doubled light, ω _p is the frequency of pump light, ω _s is the frequency of signal light, and ω _i is the frequency of converted idler light.

FIG. 6 is a schematic diagram of quasi-phase matching between pump light and an optical signal based on the cascaded sum and difference-frequency generation (cascaded sum and difference-frequency generation, SFG+DFG) second-order cascaded nonlinear effect. Among them, the first pump light, the second pump light, and the signal light are input into the PPLN optical waveguide at the same time, and the first pump light and the second pump light meet the quasi-phase matching of the sum-frequency (SFG) process Conditions, the sum-frequency reaction occurs, and the sum-frequency light ω _SF =ω _p1 -ω _p2 is generated. At the same time, the signal light and the sum-frequency light undergo difference-frequency interaction to obtain converted idler light ω _i =ω _SF -ω _s . Usually, the first pump light, the second pump light, the signal light and the converted idler light are located at the 1.55 μm wavelength band, and the sum frequency light is located at the 0.77 μm wavelength band. According to the principle of energy conservation, the wavelengths of the signal light, the first pump light, the second pump light and the frequency light, and the converted idler light satisfy the following relationship:

SFG: 1/λ _SF = 1/λ _p1 +1/λ _p2 ;

DFG: 1/λ _i =1/λ _SH -1/λ _s ;

SFG+DFG: 1/λ _i =1/λ _p1 +1/λ _p2 −1/λ _s .

Among them, λ _p1 is the wavelength of the first pump light, λ _p2 is the wavelength of the second pump light, λ _s is the wavelength of the signal light, λ _SF is the wavelength of the sum frequency light, and λ _i is the wavelength of the converted idler light wavelength; ω is the frequency coordinate axis, ω _p1 is the frequency of the first pump light, ω _p2 is the frequency of the second pump light, ω _s is the frequency of the signal light, ω _SF is the frequency of the sum frequency light, ω _i is the frequency of the converted idler light.

The quasi-phase matching methods listed above in FIG. 4 to FIG. 6 are just examples, and this embodiment is not limited thereto.

S302: Decompose the forward light beam including TM mode converted idler light and TE mode signal light into pump light, TE mode signal light and TM mode converted idler light;

In this embodiment, after step S302, it also includes: performing wavelength selection on the pump light decomposed into pump light, TE mode signal light and TM mode converted idler light, and the wavelength is used to transmit the the received signal light.

In this embodiment, after selecting the wavelength of the pump light, it further includes: decomposing the pump light into pump light, TE mode signal light and TM mode converted idler light for gain amplification. Since amplifying the pump light can offset the consumption of the pump light, a sufficient amount of pump light is guaranteed to be transmitted.

S303: Convert the TE mode signal light into a TM mode signal light, and convert the TM mode converted idler light into the TE mode converted idler light;

In this embodiment, the conversion of the light mode in step S303 is realized by optical rotation.

S304: Reversely (clockwise) multiplex the pump light, TM mode signal light, and TE mode converted idler light to generate inverse multiplexed light, and perform quasi-phase matching on the inversely multiplexed light, generating a reverse beam comprising a TM mode-converted idler and a TE mode-converted idler;

S305: Decompose the reverse light beams of the TM mode converted idler light and TE mode converted idler light into pump light, TE mode converted idler light and TM mode converted idler light.

FIG. 7 is a flowchart of an optical signal transmission method provided by another embodiment of the present invention. In this embodiment, as shown in FIG. 7, the method further includes:

S306: Filter the decomposed TE mode-converted idler light and TM mode-converted idler light.

In this embodiment, since the signal light cannot be fully utilized in practical applications, a small amount of signal light remains in the decomposed TE mode-converted idler light and TM mode-converted idler light, so the filtering here The method is to filter out a small amount of remaining signal light to obtain TE mode-converted idler light and TM mode-converted idler light.

The beneficial effect of the embodiment of the present invention is that the TE mode and TM mode of light are automatically synchronized through optical rotation; no expensive external cavity laser is needed to provide pump light; the system has the advantages of stable system, simple optical path structure, and high conversion efficiency.

Embodiment two

An embodiment of the present invention also provides an optical signal transmission device, which will be described in detail below with reference to the accompanying drawings.

FIG. 8 is a schematic diagram of an optical signal transmission device according to an embodiment of the present invention. The device includes: a first multiplexing and demultiplexing unit 801, a matching unit 802, a second multiplexing and demultiplexing unit 803, and an optical rotation unit 804. ,in:

The first multiplexing and demultiplexing unit 801 is used to forward multiplex the received signal light and the pump light generated by the laser to generate forward multiplexed light, and transmit the forward multiplexed light to the matching unit 802 .

In this embodiment, the pump light is lased when the resonance condition for pump light generated by lasing is satisfied.

In this embodiment, the first multiplexing and demultiplexing unit 801 can be a multiplexing and demultiplexing device, and the multiplexing and demultiplexing device includes 3 ports, wherein the first port is used to receive The signal light input by the detector; the second port is used to receive the pump light generated by lasing; the third port is used to transmit the forward multiplexed light generated according to the signal light and pump light to the matching unit 802 .

The matching unit 802 is used to perform quasi-phase matching on the forward multiplexed light, generate a forward beam containing TM mode conversion idler light and TE mode signal light, and transmit the forward beam to the second multiplexer demultiplexing unit 803 .

In this embodiment, the matching unit 802 may be a PPLN optical waveguide. The PPLN optical waveguide can be fabricated using the direct bond sum technique. The PPLN optical waveguide prepared by the direct bonding technology has a strong confinement effect on the optical field, and the PPLN optical waveguide prepared by the direct bonding technology supports both TM and TE mode optical transmission. Fig. 9 is a direct bonding PPLN optical waveguide provided by Embodiment 2 of the present invention, wherein "0" in Fig. 9 is the coordinate origin, "x", "y", and "z" are coordinate axes, and the lining of this optical waveguide The bottom is a lithium niobate wafer, and the waveguide layer is a Z-cut periodic poled zinc-doped lithium niobate wafer. The substrate and waveguide layer are fabricated by direct bonding. Then cut it into a ridge waveguide structure by diamond scribing. In fact, using other optical waveguides capable of simultaneously transmitting TE and TM modes in the example of the present invention can also solve the problem of polarization correlation, but since the PPLN optical waveguide can transmit both TM mode and TE mode, and the signal light and pump The confinement effect of the Pu light is very good, which can make the light concentrated in the waveguide for transmission, which is beneficial to improve the conversion efficiency, so the PPLN optical waveguide is given priority. Signal light and pump light have a difference frequency response in the PPLN optical waveguide. In order to achieve effective wavelength conversion, this requires that the polarization period Λ of the PPLN optical waveguide must satisfy the quasi-phase matching condition in the difference frequency process at the same time.

The second multiplexing and demultiplexing unit 803 is used to receive the forward light beam that contains the TM mode conversion idler light and the TE mode signal light transmitted from the matching unit 802, and decompose the forward light beam into pump light, TE mode The signal light and TM mode-converted idler light are transmitted to the optical rotation unit 804 .

In this embodiment, the second multiplexing and demultiplexing unit 803 can be a multiplexing and demultiplexing device, and the multiplexing and demultiplexing device includes 3 ports, wherein the first port is used to receive the matching unit 802 The input forward light beam comprising TM mode converted idler light and TE mode signal light is demultiplexed and decomposed into pump light, TE mode signal light and TM mode converted idler light ; the second port is used to output the pump light; the third port is used to output the converted idler light of the TM mode and the signal light of the TE mode.

The optical rotation unit 804 is used to receive the TE mode signal light and the TM mode conversion idler light transmitted from the second multiplexing and demultiplexing unit 803, and convert the TE mode signal light into a TM mode signal light, and convert the TM mode converted idler light is converted to TE mode converted idler light.

In this embodiment, the optical rotation unit 804 is a Faraday rotation unit, such as a Faraday rotation mirror. The optical rotation unit 804 receives the converted idler light and the TE mode signal light of the TM mode output from the third port of the second multiplexing and demultiplexing unit 803, converts the TE mode signal light into a TM mode signal light, and Said TM mode converted idler light is converted into TE mode converted idler light.

The optical rotation unit 804 transmits the TM mode signal light and the TE mode converted idler light from the third port of the second multiplexing and demultiplexing unit 803 to the second multiplexing and demultiplexing unit 802 .

The second multiplexing and demultiplexing unit 802 is also used to inversely multiplex the pump light, TM mode signal light and TE mode converted idler light to generate inverse multiplexed light, and The inverse multiplexed light is output from the first port of the second multiplexing and demultiplexing unit 803 to the matching unit 802 .

The matching unit 802 is further used to carry out quasi-phase matching on the inverse multiplexed light, generate a reverse beam containing TM mode conversion idler light and TE mode conversion idler light, and then convert the TM mode conversion The idler light and the reverse light beam of the TE mode-converted idler light are transmitted to the third port of the first multiplexing/demultiplexing unit 801 for demultiplexing.

The first multiplexing and demultiplexing unit 801 is also used to decompose into pump light, TE mode converted idler light and TM mode converted idler light. Wherein, the second port of the first multiplexing and demultiplexing unit 801 outputs pump light, and the first port of the first multiplexing and demultiplexing unit 801 outputs TM mode conversion idler light and TE mode conversion idler light to the optical ring device.

The beneficial effect of the embodiment of the present invention is that the automatic synchronization of the TE mode and the TM mode of the light is realized by using the optical rotation unit; the pump light is generated by the lasing of the ring cavity laser including the PPLN optical waveguide, which can provide pumping without an expensive external cavity laser Light, which provides the performance of the system, has the advantages of system stability, simple optical path structure, and high conversion efficiency.

Embodiment Three

An embodiment of the present invention also provides an optical signal transmission device, which will be described in detail below with reference to the accompanying drawings.

FIG. 10 is a schematic diagram of an optical signal transmission device according to an embodiment of the present invention. In addition to the components of the second embodiment, the optical signal transmission device of this embodiment also includes: a filtering unit 805, a polarization control unit 806 and optical amplification unit 807, wherein:

The filtering unit 805 is used to filter the demultiplexed signal light, TE mode converted idler light and TM mode converted idler light to obtain TE mode converted idler light and TM mode converted idler light.

In this embodiment, since the signal light cannot be fully utilized in practical applications, a small amount of signal light remains in the decomposed TE mode-converted idler light and TM mode-converted idler light, so the filtering here It is to filter out a small amount of remaining signal light to obtain TE mode converted idler light and TM mode converted idler light.

In this embodiment, the filtering unit 805 may be a filter.

The polarization control unit 806 is used to adjust the polarization state of the pump light to output in TM mode.

In this embodiment, the bias control unit 806 may be a bias controller.

The optical amplification unit 807 is configured to amplify the pump light decomposed by the second multiplexing and demultiplexing unit.

In this embodiment, the optical amplification unit 807 may be a semiconductor optical amplifier (Semiconductor Optical Amplifier, SOA). The optical amplification unit 807 decomposes the pump light into pump light, TE mode signal light and TM mode converted idler light for gain amplification. Since amplifying the pump light can offset the consumption of the pump light, a sufficient amount of pump light is guaranteed to be transmitted.

The beneficial effect of the embodiments of the present invention is that the pumping light is generated by the lasing of the ring cavity laser including the PPLN optical waveguide, without the need for an expensive external cavity laser to provide the pumping light; the polarization control unit adjusts the polarization state of the pumping light to TM Mode output; the optical amplifier unit is used to amplify the pump light to ensure sufficient pump light for transmission; it has the advantages of stable system, simple optical path structure and high conversion efficiency.

Embodiment four

An embodiment of the present invention also provides an optical signal transmission device, which will be described in detail below with reference to the accompanying drawings.

FIG. 11 is a schematic diagram of an optical signal transmission device provided by an embodiment of the present invention. The optical signal transmission device of this embodiment includes, in addition to the components of the foregoing second or third embodiment, a wavelength selection unit 808 configured to select the wavelength of the pumping light.

FIG. 12 is a schematic structural diagram of an optical signal transmission device provided by an embodiment of the present invention. In this embodiment, as shown in FIG. 12 , 1201 is an optical circulator, and signal light is input from the optical circulator to the first multiplexing and demultiplexing device 1202 . The optical rotation unit 803 in FIG. 11 is specifically the Faraday rotator 1205, and the filtering unit 805 in FIG. 11 is specifically the filter 1209; the first multiplexing and demultiplexing unit 801 in FIG. 11 is the first multiplexing and demultiplexing device 1202 , the first port of the first multiplexing demultiplexer 1202 is 2-1, the second port of the first multiplexing demultiplexer 1202 is 2-2, the third port of the first multiplexing demultiplexer 1202 is 2-3; the matching unit 802 in Fig. 11 is a PPLN optical waveguide 1203; the second multiplexing and demultiplexing unit 801 in Fig. 11 is the first multiplexing and demultiplexing device 1204, and the first multiplexing and demultiplexing device The first port of 1202 is 2-1, the second port of the second multiplexing and demultiplexing device 1204 is 2-2, and the third port of the second multiplexing and demultiplexing device 1204 is 2-3; among Fig. 11 The wavelength selection unit 808 is a wavelength selector 1206; the optical amplification unit 807 in FIG. 11 is specifically a semiconductor optical amplifier 1207; the polarization control unit 806 in FIG.

In this embodiment, the first multiplexer/demultiplexer 1204, the PPLN optical waveguide 1203, the second multiplexer/demultiplexer 1204, the wavelength selector 1206, the semiconductor optical amplifier 1207 and the polarization controller 1208 jointly form a ring cavity laser. When the ring cavity laser satisfies the resonance condition for lasing to generate pumping light, it can be lased to generate pumping light.

FIG. 13 is a schematic structural diagram of the first multiplexing and demultiplexing device. The first multiplexer/demultiplexer 1202 is composed of a one-to-three optical wavelength division multiplexer 13a and a one-to-two optical wavelength division multiplexer 13b cascaded.

FIG. 14 is a schematic structural diagram of the second multiplexing and demultiplexing device. The second multiplexer/demultiplexer 1204 is composed of a one-to-three optical wavelength division multiplexer 14a and a one-to-two optical wavelength division multiplexer 14b cascaded.

FIG. 15 is a schematic structural diagram of a wavelength selector provided by an embodiment of the present invention. In this embodiment, the wavelength selector 1206 is a single wavelength selector, which is composed of a first tunable optical attenuator 15a and a first tunable filter 15b, and light waves can be bidirectionally transmitted in the single wavelength selector. The first tunable filter 15b is used to select the desired wavelength, for example, in this embodiment, the light of the output wavelength is selected, and the first tunable attenuator 15a is used to properly adjust the loss of the selected wavelength corresponding to the laser light in the ring cavity and then control The optical power of the laser pumping light, the positions of the adjustable optical attenuator 15a and the adjustable filter 15b can be interchanged.

The beneficial effect of the embodiments of the present invention is that the pumping light is generated by the lasing of the ring cavity laser including the PPLN optical waveguide, without the need for an expensive external cavity laser to provide the pumping light; the polarization control unit adjusts the polarization state of the pumping light to TM Mode output; the optical amplifier unit pumps the light for gain amplification; the wavelength of the pumping light is selected by using a single wavelength selector; it has the advantages of stable system, simple optical path structure and high conversion efficiency.

Embodiment five

An embodiment of the present invention also provides an optical signal transmission device, which will be described in detail below with reference to the accompanying drawings.

The composition of the optical signal transmission device in this embodiment is basically the same as that in Embodiment 4, the difference is that in this embodiment, the wavelength selection unit 808 in FIG. 11 is a dual wavelength selector 1206 .

FIG. 16 is a schematic structural diagram of a wavelength selector provided by an embodiment of the present invention. Two groups of adjustable optical attenuators 16a and adjustable filters 16b are connected in series and then in parallel, and then connected in series with coupler 16c to form a multi-wavelength selector. The adjustable attenuator 16a is used to properly adjust the loss of the lasing light corresponding to the selected wavelength in the ring cavity to control the optical power of the laser pumping light. The positions of the adjustable optical attenuator 16a and the adjustable filter 16b can be interchanged.

In addition, due to the use of dual wavelength selectors, the implementation of the first multiplexing and demultiplexing unit and the second multiplexing and demultiplexing unit is different as follows.

FIG. 17 is a schematic structural diagram of the first multiplexing and demultiplexing device. The first multiplexer/demultiplexer 1202 is composed of a one-to-four optical wavelength division multiplexer 17a and two one-to-two optical wavelength division multiplexers 17b cascaded. The first port of the first multiplexing demultiplexer 1202 is 2-1, the second port of the first multiplexing demultiplexer 1202 is 2-2, and the third port of the first multiplexing demultiplexer 1202 is 2-3.

FIG. 18 is a schematic structural diagram of the second multiplexing and demultiplexing device. The second multiplexer/demultiplexer 1204 is composed of a one-to-four optical wavelength division multiplexer 18a and two one-to-two optical wavelength division multiplexers 18b cascaded.

The beneficial effect of the embodiments of the present invention is that the pumping light is generated by the lasing of the ring cavity laser including the PPLN optical waveguide, without the need for an expensive external cavity laser to provide the pumping light; the polarization control unit adjusts the polarization state of the pumping light to TM mode output; the optical amplifier unit pumps the light for gain amplification; the wavelength of the pumping light is selected by using a double wavelength selector; it has the advantages of stable system, simple optical path structure and high conversion efficiency.

Through the above description of the embodiments, those skilled in the art can clearly understand that the present invention can be realized by hardware, or by software plus a necessary general hardware platform. Based on such understanding, the technical solutions of the embodiments of the present invention can be embodied in the form of software products, which can be stored in a non-volatile storage medium (which can be CD-ROM, U disk, mobile hard disk, etc.), Several instructions are included to make a computer device (which may be a personal computer, a server, or a network device, etc.) execute the methods described in various embodiments of the present invention.

Those skilled in the art can understand that the drawing is only a schematic diagram of a preferred embodiment, and the units or processes in the drawing are not necessarily necessary for implementing the present invention.

Those skilled in the art can understand that the units in the device in the embodiment can be distributed in the device in the embodiment according to the description in the embodiment, and can also be changed and located in one or more devices different from the device in the embodiment. The units in the above embodiments can be combined into one unit, and can also be further divided into multiple subunits.

The serial numbers of the above embodiments of the present invention are for description only, and do not represent the advantages and disadvantages of the embodiments.

The above embodiments are only preferred specific implementations of the present invention, and ordinary changes, changes or substitutions made by those skilled in the art within the technical solutions of the embodiments of the present invention shall be included within the protection scope of the present invention.

Claims (11)

1. the transmission method of a light signal is characterized in that, described method comprises:

The flashlight that receives is carried out the multiplexing generation forward of forward multiplexed optical with the sharp pump light of penetrating generation, described forward multiplexed optical is carried out accurate phase matching, generate the forward beam that comprises TM pattern conversion ideler frequency light and TE mode signal light;

The forward beam of the described TM of comprising pattern conversion ideler frequency light and TE mode signal light is resolved into pump light, TE mode signal light and TM pattern conversion ideler frequency light;

Described TE mode signal light is converted to TM mode signal light, and described TM pattern conversion ideler frequency light is converted to TE pattern conversion ideler frequency light;

Described pump light, TM mode signal light and TE pattern conversion ideler frequency light are carried out inverse multiplexing generate inverse multiplexing light, described inverse multiplexing light is carried out accurate phase matching, generate the backward beam that comprises TM pattern conversion ideler frequency light and TE pattern conversion ideler frequency light;

The backward beam of described TM pattern conversion ideler frequency light and TE pattern conversion ideler frequency light is resolved into pump light, TE pattern conversion ideler frequency light and TM pattern conversion ideler frequency light.

2. method according to claim 1 is characterized in that, described method also comprises: TE pattern conversion ideler frequency light and TM pattern conversion ideler frequency light that described backward beam is decomposited filter.

3. method according to claim 1 is characterized in that, described method also comprises: the polarization state of adjusting pump light is exported with the TM pattern.

4. method according to claim 1 is characterized in that, described method also comprises: with the amplification that gains of the described pump light that resolves in pump light, TE mode signal light and the TM pattern conversion ideler frequency light.

5. method according to claim 1 is characterized in that, described method also comprises: select the pumping light wavelength, described wavelength is used for transmitting the described flashlight that receives.

6. the transmitting device of a light signal is characterized in that, comprising:

The first multiplexing and demultiplexing unit, the flashlight that is used for receiving carries out the multiplexing generation forward of forward multiplexed optical with the sharp pump light of penetrating generation;

Matching unit is used for described forward multiplexed optical is carried out accurate phase matching, generates the forward beam that comprises TM pattern conversion ideler frequency light and TE mode signal light;

The second multiplexing and demultiplexing unit is used for the forward beam of the described TM of comprising pattern conversion ideler frequency light and TE mode signal light is resolved into pump light, TE mode signal light and TM pattern conversion ideler frequency light;

The optically-active unit is used for described TE mode signal light is converted to TM mode signal light, and described TM pattern conversion ideler frequency light is converted to TE pattern conversion ideler frequency light;

The second multiplexing and demultiplexing unit is used for that also described pump light, TM mode signal light and TE pattern conversion ideler frequency light are carried out inverse multiplexing and generates inverse multiplexing light;

Described matching unit is further used for described inverse multiplexing light is carried out accurate phase matching, generates the backward beam that comprises TM pattern conversion ideler frequency light and TE pattern conversion ideler frequency light;

The first multiplexing and demultiplexing unit also is used for the backward beam of the described TM of comprising pattern conversion ideler frequency light and TE pattern conversion ideler frequency light is resolved into pump light, TE pattern conversion ideler frequency light and TM pattern conversion ideler frequency light.

7. device according to claim 6 is characterized in that, described device also comprises: filter element, the TE pattern conversion ideler frequency light and the TM pattern conversion ideler frequency light that are used for described backward beam is decomposited filter.

8. device according to claim 6 is characterized in that, described device also comprises: the polarization control module, the polarization state that is used for the adjustment pump light is exported with the TM pattern.

9. device according to claim 6 is characterized in that, described device also comprises: Optical Amplifier Unit is used for the pump light that described the second multiplexing and demultiplexing unit decomposition the goes out amplification that gains.

10. device according to claim 6 is characterized in that, described device also comprises: wavelength selection unit is used for selecting the pumping light wavelength.

11. device according to claim 10 is characterized in that, described wavelength selection unit comprises single wavelength selection unit or dual wavelength selected cell.

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