CN106209239A - Microwave photon converter - Google Patents

Abstract

The present invention provides a kind of microwave photon converter, and including first phase manipulator, second phase manipulator, light filtering loop and photodetector, first phase manipulator carries out phase-modulation for using first signal of telecommunication to light carrier；The optical signal that first phase manipulator is exported by second phase manipulator for using second signal of telecommunication carries out phase-modulation；Light filtering loop is used for Brillouin scattering effect based on optical fiber and stimulated Brillouin scattering effect, suppresses the light carrier in the optical signal of second phase manipulator output；Photodetector optical signal in the range of the respective frequencies exported by light filtering loop is converted into the signal of telecommunication.The present invention, by using phase-modulator, can reduce insertion loss；By using light filtering loop, Brillouin scattering effect based on optical fiber and stimulated Brillouin scattering effect, the light carrier in optical signal is suppressed, device can be simplified while eliminating light carrier bias point drifting problem, strengthen device job stability.

Description

Microwave photon converter

Technical field

The invention belongs to microwave photon field, be specifically related to a kind of microwave photon converter.

Background technology

Along with wireless communication systems such as wireless access wide band technology, radar, phased array antenna technology to bandwidth demand not Disconnected increase, the signal frequency of transmission extends to the microwave of higher frequency section, millimeter wave frequency band further, in the face of such high-frequency letter Number, the deficiency of electricity system disposal ability is all the more obvious, and therefore research and development have super large bandwidth, superelevation signal handling capacity Photonic system particularly important.Microwave photon converter, as the important functional unit of communication system, at home and abroad have also been obtained Study widely.

Traditional converter uses electro-optic intensity modulator cascade to realize under area of light signal frequency and changes, owing to intensity is adjusted Device processed is formed by Mach Zehnder interferometry structure fabrication, and therefore insertion loss is bigger；It addition, intensity modulator to there is light carrier inclined Put point drift problem, in order to eliminate the problem of bias point drift, need to be biased intensity modulator controlling, either use Power method or pilot tone system control, all can increase the complexity of device, reduce the working stability degree of device.

Summary of the invention

The present invention provides a kind of microwave photon converter, and to solve, microwave current photon converter insertion loss is relatively big, device Part complexity height and the problem of less stable.

First aspect according to embodiments of the present invention, it is provided that a kind of microwave photon converter, including first phase manipulator, Second phase manipulator, light filtering loop and photodetector, wherein said first phase manipulator is for using the first telecommunications Number light carrier is carried out phase-modulation；Described first phase is modulated by described second phase manipulator for using second signal of telecommunication The optical signal of device output carries out phase-modulation；

Described smooth filtering loop is used for Brillouin scattering effect based on optical fiber and stimulated Brillouin scattering effect, to described Light carrier in the optical signal of second phase manipulator output suppresses；Described photodetector is for filtering ring by described light Optical signal in the range of the respective frequencies of road output is converted into the signal of telecommunication.

In the optional implementation of one, described smooth filtering loop includes input equipment, optical fiber and output device, wherein Described input equipment is for inputting the optical signal of described second phase manipulator output, and passes through described optical fiber by described optical signal It is transferred to described output device；Described optical fiber transmit described second phase manipulator output optical signal time, described optical signal In light carrier as pump light, under the effect of the Brillouin scattering effect of described optical fiber produce stokes light, reversely pass Transport to described input equipment；Described stokes light is transferred to described output device by described input equipment；

Described stokes light is transferred to described optical fiber by described output device, stokes light described in described optical fiber Transmit in opposite directions with the light carrier in the optical signal of described second phase manipulator output, thus occur stimulated Brillouin scattering to imitate Should, under the effect of described stimulated Brillouin scattering effect, the light carrier in the optical signal of described second phase manipulator output obtains To suppression, the residual components in the optical signal hereafter exported by described second phase manipulator exports to described photodetector.

In the optional implementation of another kind, described input equipment is the first optical circulator, described first optical circulator On be sequentially arranged the first port, the second port and the 3rd port, the first port conduct of wherein said first optical circulator The input of described smooth filtering loop, is connected with the outfan of described second phase manipulator, the of described first optical circulator Two-port netwerk is connected with the second port of described output device by described optical fiber, the 3rd port of described first optical circulator and institute The first port stating output device connects.

In the optional implementation of another kind, described output device is the second optical circulator, described second optical circulator On be sequentially arranged the first port, the second port and the 3rd port, wherein said second closes the first port conduct of circulator First port of described output device, is connected with the 3rd port of described first optical circulator, and described second closes the of circulator Two-port netwerk, as the second port of described output device, is connected by the second port of described optical fiber with described first optical circulator Connecing, described 3rd port, as the outfan of described smooth filtering loop, is connected with the input of described photodetector.

In the optional implementation of another kind, described optical fiber is dispersion shifted optical fiber.

In the optional implementation of another kind, the optical signal of described first phase manipulator output includes that light carrier is believed Number and optical carrier after described first phase modulators modulate.

In the optional implementation of another kind, the optical signal of described second phase manipulator output includes that light carrier is believed Number, the optical carrier after described first phase modulators modulate, the light carrier after described second phase modulators modulate Signal and the optical carrier after described first phase manipulator and described second phase modulators modulate.

In the optional implementation of another kind, the optical signal of described smooth filtering loop output includes through described first phase Optical carrier after modulators modulate, the optical carrier after described second phase modulators modulate and through described first Optical carrier after phase-modulator and described second phase modulators modulate.

The invention has the beneficial effects as follows:

1, the present invention is by using cascade phase modulation device, can reduce insertion loss；By using light filtering loop, and Make light filtering loop Brillouin scattering based on optical fiber effect and stimulated Brillouin scattering effect, the light carrier in optical signal is entered Row suppression, can simplify device while eliminating light carrier bias point drifting problem, strengthen device job stability, and can To reduce the light carrier interference to output optical signal, thus reduce input electrical signal leakage in the output signal；

2, the present invention is by using optical circulator to control optical signal transmission in light filtering loop so that whole converter Assembly is simpler.

Accompanying drawing explanation

Fig. 1 is an embodiment circuit diagram of microwave photon converter of the present invention；

Fig. 2 is an embodiment schematic diagram of microwave photon converter frequency spectrum processing process of the present invention；

Fig. 3 is that the normalization conversion gain of microwave photon converter of the present invention is shown with the variation relation of optical carrier suppression coefficient It is intended to.

Detailed description of the invention

For the technical scheme making those skilled in the art be more fully understood that in the embodiment of the present invention, and make the present invention real Execute the above-mentioned purpose of example, feature and advantage can become apparent from understandable, below in conjunction with the accompanying drawings to technical side in the embodiment of the present invention Case is described in further detail.

In describing the invention, unless otherwise prescribed and limit, it should be noted that term " connects " should do broad sense manage Solve, for example, it may be mechanically connected or electrical connection, it is also possible to be the connection of two element internals, can be to be joined directly together, it is possible to To be indirectly connected to by intermediary, for the ordinary skill in the art, can understand as the case may be above-mentioned The concrete meaning of term.

See Fig. 1, for an embodiment circuit diagram of microwave photon converter of the present invention.This microwave photon converter Can include first phase manipulator 110, second phase manipulator 120, light filtering loop 130 and photodetector 140, first The first input end input light carrier of phase-modulator 110, the second input inputs first signal of telecommunication, and it can use the first electricity Signal carries out phase-modulation to light carrier；The first input end of second phase manipulator 120 inputs second signal of telecommunication, the second input End connects the outfan of first phase manipulator 110, and it can use second signal of telecommunication to export first phase manipulator 110 Optical signal carries out phase-modulation, wherein the optical signal of first phase manipulator 110 output can include optical carrier and Optical carrier after first phase manipulator 110 is modulated.If setting the frequency of optical carrier as f_c, the frequency of first signal of telecommunication Rate is f_RF, then the frequency of the optical carrier after first phase manipulator 110 is modulated can be f_c±f_RF。

The input of light filtering loop 130 is connected with the outfan of second phase manipulator 120, and it can be based on optical fiber Brillouin scattering effect and stimulated Brillouin scattering effect, to the light carrier in the optical signal of second phase manipulator 120 output Suppressing, wherein the optical signal of second phase manipulator 120 output can include optical carrier, through first phase manipulator 110 modulation after optical carrier, through second phase manipulator 120 modulate after optical carrier and through first phase modulate Optical carrier after device 110 and second phase manipulator 120 modulation.Similarly, if setting the frequency of optical carrier as f_c, the The frequency of one signal of telecommunication is f_RF, the frequency of second signal of telecommunication is f_LO, then the light carrier after first phase manipulator 110 is modulated The frequency of signal can be f_c±f_RF, the frequency of the optical carrier after second phase manipulator 120 is modulated can be f_c± f_LO, the frequency of the optical carrier after first phase manipulator 110 and second phase manipulator 120 are modulated can be f_c± (f_RF-f_LO)。

The input of photodetector 140 is connected with the outfan of light filtering loop 130, and it can be by light filtering loop Optical signal in the range of the respective frequencies of 130 outputs is converted to the signal of telecommunication, and wherein the optical signal of light filtering loop 130 output is permissible Including through first phase manipulator 110 modulate after optical carrier, through second phase manipulator 120 modulate after light carrier letter Number and optical carrier after first phase manipulator 110 and second phase manipulator 120 are modulated.

In the present embodiment, light carrier can be produced by light source generators such as laser instrument.This light filtering loop 130 can include Input equipment 131, optical fiber 132 and output device 133, wherein the first port of input equipment 131 is as light filtering loop 130 Input, can be connected with the outfan of second phase manipulator 120, and the second port is by optical fiber 132 and output device 133 Second port connects, and the 3rd port is connected with the first port of output device 133, and the 3rd port of output device 133 is as light The outfan of filtering loop 130, can be connected with the input of photodetector 140.Input equipment 131 is in input second phase After the optical signal of manipulator 120 output, optical fiber 132 can be passed through by this optical signal transmission to output device 133, thus by exporting Device 133 is transferred to photodetector 140.Owing to the optical signal of second phase manipulator 120 output can include that light carrier is believed Number, through first phase manipulator 110 modulate after optical carrier, through second phase manipulator 120 modulate after light carrier letter Number and optical carrier after first phase manipulator 110 and second phase manipulator 120 are modulated, and at these signals The intensity of middle optical carrier is the strongest, and therefore optical fiber 132 is when transmitting the optical signal of second phase manipulator 120 output, this light Optical carrier in signal can produce stoke as pump light under the effect of the Brillouin scattering effect of optical fiber 132 This light, reverse transfer is to input equipment 131.Input equipment 131, can be by this stokes light after receiving stokes light It is transferred to output device 133.Hereafter, stokes light can be transferred to optical fiber 132 by output device 133, should in optical fiber 132 Light carrier in the optical signal that stokes light and second phase manipulator 120 export transmits in opposite directions, thus is excited background of cloth Deep pool scattering effect, under the effect of stimulated Brillouin scattering effect, the light in the optical signal of second phase manipulator 120 output carries Ripple can be inhibited.

Wherein, this input equipment 131 can be the first optical circulator, and optical fiber 132 can be dispersion shifted optical fiber, output dress Putting 133 can be the second optical circulator.The first port 1a, the second port can be sequentially arranged on first optical circulator 131 1b and the 3rd port 1c, wherein the second port 1b is the lower Single port of the first port 1a, and the 3rd port 1c is the second port 1b Lower Single port.Input-output characteristic according to optical circulator: optical signal, can only be from this input port when arbitrary port inputs Lower Single port exports, it is known that the optical signal of input to the first port 1a can only be from the second port 1b output, and input is to the second port The optical signal of 1b can only be from the 3rd port 1c output.Also be sequentially arranged on second optical circulator 133 first port 2a, second Port 2b and the 3rd port 2c, wherein the second port 2b is the lower Single port of the first port 2a, and the 3rd port 2c is the second port The lower Single port of 2b.Similarly input to the first port 2a optical signal can only from second port 2b output, input to the second end The optical signal of mouth 2b can only be from the 3rd port 2c output.First port 1a of this first optical circulator 131 is as light filtering loop The input of 130, is connected with the outfan of second phase manipulator 120, and the second port 1b connects second ring of light by optical fiber 132 Second port 2b of shape device 133, the 3rd port 1c connect the first port 2a of the second optical circulator 133, the second optical circulator 133 The 3rd port 2c as the outfan of light filtering loop 130, be connected with the input of photodetector 140.

Operationally, the optical signal of second phase manipulator 120 output can be from first ring of light for above-mentioned smooth filtering loop 130 First port 1a input of shape device 131, then from the second port 1b output, then it is input to second via dispersion shifted optical fiber 132 Second port 2b of optical circulator 133, finally from the 3rd port 2c output, the optical signal of the 3rd port 2c output can enter into In photodetector 140.Owing to the light carrier in the optical signal of output after two-stage phase-modulation still has the highest signal Intensity, after therefore the optical signal of second phase manipulator 120 output enters into dispersion shifted optical fiber 132, light carrier is as pumping Light can produce the stokes light of reverse transfers, Si Tuo under the effect of dispersion shifted optical fiber 132 spontaneous brillouin scattering effect Ke Si light is transferred to the first port 1b from dispersion shifted optical fiber 132 in the counterclockwise direction and enters the first optical circulator 131, via 3rd port 1c output after enter directly into the second optical circulator 133 from the first port 2a, from first port 2a input this Lentor light, from the second port 2b output of the second optical circulator 133, enters back in dispersion shifted optical fiber 132.From the second port The stokes light of 2b output and the light carrier in the optical signal of second phase manipulator 120 output are at dispersion shifted optical fiber 132 In transmit in opposite directions, occur stimulated Brillouin scattering response, the energy of optical carrier under the effect of stimulated Brillouin scattering effect Measure decay greatly, therefore enter into, from the 3rd port 2c output, the carrier wave that the optical signal photodetector 140 comprises Component will obtain the strongest suppression.

As seen from the above-described embodiment, the present invention, by using cascade phase modulation device, can reduce insertion loss；By adopting Use light filtering loop, and make light filtering loop Brillouin scattering based on optical fiber effect and stimulated Brillouin scattering effect, to light Light carrier in signal suppresses, and can simplify device, strengthen device while eliminating light carrier bias point drifting problem Job stability, and the light carrier interference to output optical signal can be reduced, thus reduce input electrical signal in output signal In leakage.

See Fig. 2, for an embodiment schematic diagram of microwave photon converter frequency spectrum processing process of the present invention.Figure medium frequency For f_cOptical carrier to produce frequency via first phase manipulator 110 be f_cWith f_c±f_RFOptical signal component (high-order sideband Much smaller relative to single order sideband intensity, therefore can neglect)；First phase manipulator 110 output optical signal via It is f that second phase manipulator 120 produces frequency_c、f_c±f_RF、f_c±f_LO、f_c±(f_RF-f_LO) optical signal component, then entered color To optical carrier component, (i.e. frequency is f to the light filtering loop 130 that scattered shifted fiber 132 and optical circulator 131,133 build_cLight Component of signal) suppress, it is f that remaining component of signal beat frequency in photodetector 140 produces frequency_RF-f_LOIntermediate frequency letter Number output.

Can be seen that the main functional unit of whole scheme comprises two-stage phase-modulation and three parts of carrier wave suppression loop, Through two-stage phase-modulation, microwave signal (i.e. first signal of telecommunication) and local oscillation signal (i.e. second signal of telecommunication) are loaded into light carrier After upper, the light field of optical signal can be expressed as:

$E\left(t\right)=\sqrt{P_{opt}{L}_{opt}}\exp \{j2{\mathrm{\πf}}_{c}t+{\mathrm{jm}}_{1}cos\left(2{\mathrm{\πf}}_{RF}t\right)\}\exp \{j2{\mathrm{\πf}}_{c}t+{\mathrm{jm}}_{2}cos\left(2{\mathrm{\πf}}_{LO}t\right)\}---\left(1\right)$

P in formula_optFor the power of optical carrier, L_opt(include that phase-modulator 1 and phase place are adjusted for link light insertion loss The attenuated optical signal that the intrinsic Insertion Loss of device 2 processed and carrier wave suppression optical fiber loop bring), m₁And m₂It is respectively microwave signal and basis Shake phase modulation coefficient (the wherein m of signal₁=V_RF/V_π1,m₂=V_LO/V_π2,V_RFAnd V_LOIt is respectively microwave signal and local oscillation signal Amplitude, V_π1And V_π2It is respectively phase-modulator 1 and the half-wave voltage of phase-modulation 2).Formula (1) is pressed Bessel function exhibition Open, can be written as:

$\begin{array}{c}E\left(t\right)=\sqrt{P_{opt}{L}_{opt}}\exp \left\{j2{\mathrm{\πf}}_{c}t\right\}\\ \×\underset{p=-\mathrm{\∞}}{\overset{\mathrm{\∞}}{\Σ}}{j}^p{J}_p\left(m_1\right)\exp \left\{j2{\mathrm{p\πf}}_{RF}t\right\}\underset{q=-\mathrm{\∞}}{\overset{\mathrm{\∞}}{\Σ}}{j}^q{J}_q\left(m_2\right)\exp \left\{j2{\mathrm{q\πf}}_{LO}t\right\}\end{array}---\left(2\right)$

In formula, J_pAnd J_qRepresent p rank and q rank Bessel function of the first kind respectively.Ignore high-order small intensity sideband signals, and Introduce the stimulated Brillouin scattering effect inhibitory action to optical carrier, then understand the of the second optical circulator 133 according to Fig. 2 The light field of Two-port netwerk 2c output optical signal is expressed as:

$\begin{array}{c}E\left(t\right)=\sqrt{P_{opt}{L}_{opt}}\exp \left\{j2{\mathrm{\πf}}_{c}t\right\}\\ \×\left(\begin{array}{c}{\mathrm{\αJ}}_0\left(m_1\right)J_0\left(m_2\right)-{\mathrm{jJ}}_0\left(m_2\right)J_{-1}\left(m_1\right)\exp \{-j2{\mathrm{\πf}}_{RF}t\}+{\mathrm{jJ}}_0\left(m_2\right)J_1\left(m_1\right)\exp \left\{j2{\mathrm{\πf}}_{RF}t\right\}\\ -{\mathrm{jJ}}_0\left(m_1\right)J_{-1}\left(m_2\right)\exp \{-j2{\mathrm{\πf}}_{LO}t\}+{\mathrm{jJ}}_0\left(m_1\right)J_1\left(m_2\right)\exp \left\{j2{\mathrm{\πf}}_{LO}t\right\}\\ +J_1\left(m_1\right)J_{-1}\left(m_2\right)\exp \left\{j2\mathrm{\π}(f_{RF}-f_{LO})t\right\}+J_1\left(m_2\right)J_{-1}\left(m_1\right)\exp \{-j2\mathrm{\π}(f_{RF}-f_{LO})t\}\end{array}\right)\end{array}---\left(3\right)$

In formula α be light carrier rejection coefficient (g_BFor optical fiber Brillouin gain coefficient, L_eff And A_effIt is respectively optical fiber effective length and effective core area).By microwave signal knowable to formula (3) as local oscillation signal, it The fundamental frequency signal that produces of upper side band and light carrier beat frequency, the intensity phase of the fundamental frequency signal that lower sideband produces with light carrier beat frequency Equiphase is contrary, is cancelled completely under the effect interfered, and therefore the last outfan at photodetector can be obtained by Frequency is f_RF-f_LOIntermediate-freuqncy signal, prevent simultaneously microwave signal and local oscillation signal to intermediate-freuqncy signal reveal.

See Fig. 3, for the normalization conversion gain of microwave photon converter of the present invention with the change of optical carrier suppression coefficient Relation schematic diagram.As can be seen from Figure, along with the increase of carrier wave suppression degree, the output intensity of intermediate-freuqncy signal is the highest.

Those skilled in the art, after considering description and putting into practice invention disclosed herein, will readily occur to its of the present invention Its embodiment.The application is intended to any modification, purposes or the adaptations of the present invention, these modification, purposes or Person's adaptations is followed the general principle of the present invention and includes the undocumented common knowledge in the art of the present invention Or conventional techniques means.Description and embodiments is considered only as exemplary, and true scope and spirit of the invention are by following Claim is pointed out.

It should be appreciated that the invention is not limited in precision architecture described above and illustrated in the accompanying drawings, and And various modifications and changes can carried out without departing from the scope.The scope of the present invention is only limited by appended claim.

Claims (8)

1. a microwave photon converter, it is characterised in that include that first phase manipulator, second phase manipulator, light filter Loop and photodetector, wherein said first phase manipulator carries out phase place tune for using first signal of telecommunication to light carrier System；The optical signal that described first phase manipulator is exported by described second phase manipulator for using second signal of telecommunication carries out phase Position modulation；

Described smooth filtering loop is used for Brillouin scattering effect based on optical fiber and stimulated Brillouin scattering effect, to described second Light carrier in the optical signal of phase-modulator output suppresses；Described photodetector is for by defeated for described smooth filtering loop Optical signal in the range of the respective frequencies gone out is converted into the signal of telecommunication.

Microwave photon converter the most according to claim 1, it is characterised in that described smooth filtering loop includes input dress Put, optical fiber and output device, wherein said input equipment is for inputting the optical signal of described second phase manipulator output, and leads to Cross described optical fiber by described optical signal transmission to described output device；Described optical fiber is transmitting the output of described second phase manipulator Optical signal time, the light carrier in described optical signal is as pump light, under the effect of the Brillouin scattering effect of described optical fiber Produce stokes light, reverse transfer to described input equipment；Described stokes light is transferred to described by described input equipment Output device；

Described stokes light is transferred to described optical fiber by described output device, stokes light and institute described in described optical fiber The light carrier stated in the optical signal of second phase manipulator output transmits in opposite directions, thus stimulated Brillouin scattering effect occurs, Under the effect of described stimulated Brillouin scattering effect, the light carrier in the optical signal of described second phase manipulator output is pressed down System, the residual components in the optical signal hereafter exported by described second phase manipulator exports to described photodetector.

Microwave photon converter the most according to claim 2, it is characterised in that described input equipment is the first light annular Device, described first optical circulator has been sequentially arranged the first port, the second port and the 3rd port, wherein said first ring of light First port of shape device, as the input of described smooth filtering loop, is connected with the outfan of described second phase manipulator, institute The second port stating the first optical circulator is connected with the second port of described output device by described optical fiber, described first ring of light 3rd port of shape device is connected with the first port of described output device.

Microwave photon converter the most according to claim 3, it is characterised in that described output device is the second light annular Device, described second optical circulator has been sequentially arranged the first port, the second port and the 3rd port, wherein said second cyclization First port of shape device, as the first port of described output device, is connected with the 3rd port of described first optical circulator, institute State second port, second port as described output device of the second pass circulator, by described optical fiber and described first ring of light Second port of shape device connects, and described 3rd port is as the outfan of described smooth filtering loop, with described photodetector Input connects.

Microwave photon converter the most as claimed in any of claims 1 to 4, it is characterised in that described optical fiber is color Dissipate shifted fiber.

Microwave photon converter the most according to claim 1, it is characterised in that the light of described first phase manipulator output Signal includes optical carrier and the optical carrier after described first phase modulators modulate.

Microwave photon converter the most according to claim 1, it is characterised in that the light of described second phase manipulator output Signal includes optical carrier, optical carrier after described first phase modulators modulate, modulates through described second phase Optical carrier after device modulation and the light after described first phase manipulator and described second phase modulators modulate carry Ripple signal.

Microwave photon converter the most according to claim 1, it is characterised in that the optical signal of described smooth filtering loop output Including the optical carrier after described first phase modulators modulate, light carrier after described second phase modulators modulate Signal and the optical carrier after described first phase manipulator and described second phase modulators modulate.