CN103176278B - Optical mixer for reflective coherent receivers - Google Patents

Abstract

The invention relates to an optical mixer for reflective coherent receives, belongs to optical devices of optical fiber communication and solves the problem that existing optical mixers are non-compact in structure and poor in temperature stability. A polarization separator, a 1/2 wave plate, a phase shift plate, a first shift crystal, a 1/4 wave plate and a combined reflecting mirror are sequentially arranged along an incident light path, and the 1/4 wave plate, the first shift crystal, the 1/2 wave plate and a second shift crystal are sequentially arranged on a reflecting light path of the combined reflecting mirror, wherein the 1/2 wave plate, the first shift crystal and the 1/4 wave plate are shared devices. Polarization separating is realized through a polarization separation prism, 90-degree phase shift is realized through the phase shift plate, safe-phase and orthogonal output light required is obtained by adopting the reflecting structure, birefringent crystals, the 1/4 wave plate, the 1/2 wave plate and the combined reflecting mirror, and polarization and phase diversity control is realized. The optical mixer is compact in integral structure, mature in processing technique of various devices, good in temperature stability and high in polarization extinction ratio, and can be used for optical signal coherent modulation by advanced modulation formats and polarization multiplexing way in the optical fiber communication.

Description

A kind of reflective coherent receiver optical mixer

Technical field

The invention belongs to the optical device of optical fiber communication, be specifically related to a kind of reflective coherent receiver optical mixer, for employing palarization multiplexing mode that optical fiber is transmitted and the light signal of advanced modulation formats, realize coherent reception and demodulation.

Background technology

Along with optical fiber telecommunications system is constantly upgraded, the light signal transmitting in optical fiber has been brought into use advanced modulation formats and has been presented the feature of the whole audience (amplitude, frequency, phase place, polarization) carry information in recent years.For this feature, at the receiving end of system, must use coherence detection could obtain the full detail that light signal carries.Hexadecimal quadrature Modulation and Amplitude Modulation (DP-16QAM) form that adopts palarization multiplexing is that in existing commercial long distance High-speed optical fiber telecommunications system, a kind of typical optical multiplexed signal is used and modulation system.In said system in order to realize receiving and demodulating of signal, need to use an optical mixer that local oscillator light is concerned with and is mixed with the flashlight receiving, complete local oscillator light and flashlight polarization and phase diversity receiving function, after opto-electronic conversion and balance detection, by subsequent process circuit, realized the demodulation of signal and export again.

In optical mixer, the electric field intensity E of input signal light _scan be decomposed into the polarized component E of two quadratures _sxand E _sy, with local oscillator light E _lOmix and after the diversity reception of polarization and phase place, at output terminal, should have eight corresponding components, being designated as respectively E _sx+ E _lO, E _sx-E _lO, E _sx+ iE _lO, E _sx-iE _lO, E _sy+ E _lO, E _sy-E _lO, E _sy+ iE _lO, E _sy-iE _lO.The structure (2 * 8 structure) of two input ports of flashlight and local oscillator light that have been this kind of optical mixer correspondence, eight output ports.

In the Chinese invention patent application of application number 200920073027.8 " double wave sheet phase place is adjusted birefringence space light bridge ", a kind of 2 * 4 optical mixers for the communication of free space laser coherence have been proposed.Owing to not carrying out polarization diversity control, thus the polarization state of input signal light be there are certain requirements, can not be for adopting the optical fiber telecommunications system of palarization multiplexing.

The Chinese invention patent application of application number 201010572938.2 " for the crystal-type optical mixer of coherent light communication " has proposed a kind of 2 * 8 structured light mixers based on birefringece crystal, can be used for the coherent reception of DP-QPSK signal.But because this device employing transmission-type structure causes, device shape is long and narrow, structure is not compact.

The U.S. Patent application of application number 13/157379 " OPTICAL WAVEGUIDE ELEMENT; OPTICAL HYBRID CIRCUIT; AND OPTICAL RECEIVER ", a kind of optical mixer of planar waveguide-type is proposed, can realize polarization, phase diversity receiving function to light signal, but exist that coupling loss is large, polarization extinction ratio is low and the shortcoming such as temperature stability is poor.

Summary of the invention

The invention provides a kind of reflective coherent receiver optical mixer, solve the problem that existing optical mixer structure is not compact, temperature stability is poor.

A kind of reflective coherent receiver optical mixer provided by the present invention, along input path, be disposed with polarization separator, 1/2 wave plate, phase plate, the first displacement crystal, quarter wave plate and facetted mirrors, on the reflected light path of facetted mirrors, be disposed with quarter wave plate, the first displacement crystal, 1/2 wave plate, the second displacement crystal, wherein 1/2 wave plate, the first displacement crystal, quarter wave plate are common parts, it is characterized in that:

Described polarization separator is comprised of polarization separation prism and 45 degree catoptron stacks; Described polarization separation prism forms square crystal by two blocks of identical right angled isosceles triangle birefringece crystals are bonding, the logical light face of its incident is vertical with Z-direction, described 45 degree catoptrons are right angled isosceles triangle quartz crystal, the right-angle side of its right-angle side length and right angled isosceles triangle birefringece crystal is equal in length, and the hypotenuse place reflecting surface of described 45 degree catoptrons is parallel with the parting plane of described polarization separation prism;

The logical light face of described 1/2 wave plate is vertical with Z axis, and quick shaft direction and the first displacement principal section of crystal are 22.5 degree angles;

Described phase plate is upper and lower two foursquare quarter wave plates, lays respectively at after polarization separator two of local oscillator light and goes out optical position, and quick shaft direction is all parallel with the first displacement principal section of crystal;

Described the first displacement crystal is rectangular parallelepiped birefringece crystal, principal section and XOZ plane parallel, and logical light face is vertical with Z axis; Principal section is the optical axis of crystal, o light and the residing common plane of e light;

The logical light face of described quarter wave plate is vertical with Z axis, and quick shaft direction and the first displacement principal section of crystal are miter angle;

Described facetted mirrors is constituted by an isosceles trapezoid prism and two identical upper isosceles right angle prisms, lower isosceles right angle prisms, the upper bottom surface of isosceles trapezoid prism is parallel with bottom surface, and the angle of isosceles trapezoid prism left surface and right flank and bottom surface is 45 degree; The angle of upper isosceles right angle prism left surface and right flank and bottom surface is 45 degree; The angle of lower isosceles right angle prism left surface and right flank and bottom surface is 45 degree; Upper isosceles right angle prism bottom surface, lower isosceles right angle prism bottom surface are square and overlap with isosceles trapezoid prism upper bottom surface, and the seamed edge of upper isosceles right angle prism and lower isosceles right angle prism is vertical with the seamed edge of isosceles trapezoid prism;

Isosceles trapezoid prism upper bottom surface is logical light face and vertical with Z axis with bottom surface; The seamed edge of isosceles trapezoid prism is perpendicular to the principal section of the first displacement crystal;

Isosceles trapezoid prism left surface and right flank, upper isosceles right angle prism left surface and right flank, lower isosceles right angle prism left surface and right flank are reflecting surface;

Described the second displacement crystal is rectangular parallelepiped birefringece crystal, and its logical light face is vertical with Z-direction, and the second displacement principal section of crystal is parallel with the first displacement principal section of crystal, and direction of optic axis is identical; The direction of optic axis of each displacement crystal is the angle theta of optical axis and o light normal direction; Described first, second displacement crystal is single axial birefringence crystal, and in each displacement crystal, the refractive index of o light and e light is respectively n _oand n _e.

Described reflective coherent receiver optical mixer, is characterized in that:

Described first, second displacement crystal is kalzit, Yttrium Orthovanadate, α phase barium metaborate or lithium niobate;

The direction of optic axis of described first, second displacement crystal

Described reflective coherent receiver optical mixer, is characterized in that:

Described the first displacement crystal is along the length of Z direction wherein Φ is the beam diameter of flashlight and local oscillator light; In the first displacement crystal, the separating distance of o light and e light is the first displacement crystal is in the width W of directions X ₄> 2D ₁+ Φ; The first displacement crystal is in the height H in Y-direction ₄: 4 Φ < H ₄< 4D ₁one 2 Φ;

Described polarization separator is in the width W of directions X ₁> Φ, polarization separator is in the length L of Z direction ₁=H ₄/ 2;

Described 1/2 wave plate is in the width W of directions X ₂=W ₄, 1/2 wave plate is in the height H of Y-direction ₂=H ₄;

The length of side W of square quarter wave plate in described phase plate ₃: Φ < W ₃< (H ₄/ 2-Φ);

Described quarter wave plate is in the width W of directions X ₅=W ₄, quarter wave plate is in the height H of Y-direction ₅=H ₄;

The long L=H of the better-than-average waist right angle prism of described facetted mirrors seamed edge ₄/ 2, isosceles trapezoid prism bottom surface is in the width W of directions X ₆=W ₄, isosceles trapezoid prism bottom surface is in the height H of Y-direction ₆=H ₄;

Described the second displacement crystal is along the length of Z direction the separating distance of o light and e light in the second displacement crystal the second displacement crystal is in the width W of directions X ₇> D ₂+ Φ, the second displacement crystal is in the height H of Y-direction ₇=H ₄;

Parallel and distance is H along Z direction for input signal light and local oscillator light ₄/ 4; Input signal light and local oscillator light in the first displacement crystal with the distance d of the first displacement crystal right flank ₁=W ₄/ 2+D ₁, input signal light in the first displacement crystal with the first displacement crystal on the distance of end face

When the present invention is in running order, flashlight is successively by polarization separator, 1/2 wave plate, the first displacement crystal, quarter wave plate, local oscillator light is successively by polarization separator, 1/2 wave plate, phase plate, the first displacement crystal, quarter wave plate, and local oscillator light polarization direction and the first displacement principal section of crystal angle are 45 degree;

Flashlight is realized polarization separation after by polarization separator and is formed flashlight x component E _sxwith flashlight y component E _sy, local oscillator light forms local oscillator light x component E after by polarization separator _lOxwith local oscillator light y component E _lOy;

Described 1/2 wave plate is spent all light polarization rotations 45 by it; Described phase plate becomes circularly polarized light by local oscillator light x component and y component from linearly polarized light, is used for introducing needed 90 degree phase shifts;

The first described displacement crystal is by flashlight x component E _sxbe separated into o light with e light by flashlight y component E _sybe separated into o light with e light by local oscillator light x component E _lOxbe separated into o light with e light by local oscillator light y component E _lOybe separated into o light with e light

Described quarter wave plate becomes circularly polarized light by all linearly polarized lights by it, after facetted mirrors reflection, passes through successively again quarter wave plate, the first displacement crystal, 1/2 wave plate and the second displacement crystal; Described quarter wave plate becomes linearly polarized light by all circularly polarized lights by it, makes to pass through its light polarization 90-degree rotation twice totally before and after reflection; Described the first displacement crystal is above-mentioned by what be reflected back with with with and with close bundle; Described 1/2 wave plate is spent all light polarization rotations 45 by it; Described the second displacement crystal is separated with y component by the x component of light beam after 1/2 wave plate, obtain needed signal for detection of.

The present invention, as 2 * 8 optical mixers, uses polarization separation prism to carry out polarization state separation; By phase plate, realize the phase shift of 90 degree; Adopt reflective structure, use birefringece crystal, quarter wave plate, 1/2 wave plate and catoptron to obtain required homophase and quadrature output light, realize polarization, phase diversity control; Compact overall structure, each device manufacturing process is ripe, temperature stability is good, polarization extinction ratio is high, can be used for adopting in optical fiber communication advanced modulation formats and the coherent demodulation of palarization multiplexing mode light signal.

Accompanying drawing explanation

Fig. 1 is the structural representation of the embodiment of the present invention;

Fig. 2 is the schematic perspective view of facetted mirrors in the present invention;

Fig. 3 is the front elevation of facetted mirrors in the present invention;

Fig. 4 is the vertical view of facetted mirrors in the present invention.

Embodiment

Below in conjunction with drawings and Examples, to the detailed description of the invention, for the clear position of determining each device in the present invention, in Fig. 1, provide rectangular coordinate system in space XYZ.

As shown in Figure 1, embodiments of the invention, along input path, be disposed with polarization separator 1,1/2 wave plate 2, phase plate 3, the first displacement crystal 4, quarter wave plate 5 and facetted mirrors 6, on the reflected light path of facetted mirrors 6, be disposed with quarter wave plate 5, the first displacement crystal 4,1/2 wave plate 2, the second displacement crystal 7, wherein 1/2 wave plate 2, the first displacement crystal 4, quarter wave plate 5 are common parts;

Described polarization separator 1 is comprised of polarization separation prism and 45 degree catoptron stacks; Described polarization separation prism forms square crystal by two blocks of identical right angled isosceles triangle birefringece crystals are bonding, the logical light face of its incident is vertical with Z-direction, described 45 degree catoptrons are right angled isosceles triangle quartz crystal, the right-angle side of its right-angle side length and right angled isosceles triangle birefringece crystal is equal in length, and the hypotenuse place reflecting surface of described 45 degree catoptrons is parallel with the parting plane of described polarization separation prism;

The logical light face of described 1/2 wave plate 2 is vertical with Z axis, and quick shaft direction and the first displacement crystal 4 principal sections are 22.5 degree angles;

Described phase plate 3 is upper and lower two foursquare quarter wave plates, lays respectively at after polarization separator two of local oscillator light and goes out optical position, and quick shaft direction is all parallel with the first displacement crystal 4 principal sections;

Described the first displacement crystal 4 is rectangular parallelepiped birefringece crystal, principal section and XOZ plane parallel, and logical light face is vertical with Z axis; Principal section is the optical axis of crystal, o light and the residing common plane of e light;

The logical light face of described quarter wave plate 5 is vertical with Z axis, and quick shaft direction and the first displacement crystal 4 principal sections are miter angle;

As shown in Figure 2, Figure 3, Figure 4, described facetted mirrors 6 is constituted by an isosceles trapezoid prism 6-1 and two identical upper isosceles right angle prism 6-2, lower isosceles right angle prism 6-3, the upper bottom surface 6-11 of isosceles trapezoid prism 6-1 is parallel with bottom surface 6-12, and the angle of isosceles trapezoid prism 6-1 left surface 6-13 and right flank 6-14 and bottom surface 6-12 is 45 degree; The angle of upper isosceles right angle prism 6-2 left surface 6-21 and right flank 6-22 and bottom surface 6-23 is 45 degree; The angle of lower isosceles right angle prism 6-3 left surface 6-31 and right flank 6-32 and bottom surface 6-33 is 45 degree; Upper isosceles right angle prism 6-2 bottom surface 6-23, lower isosceles right angle prism 6-3 bottom surface 6-33 are square and overlap with isosceles trapezoid prism 6-1 upper bottom surface 6-11, and the seamed edge of upper isosceles right angle prism 6-2 and lower isosceles right angle prism 6-3 is vertical with the seamed edge of isosceles trapezoid prism 6-1;

Isosceles trapezoid prism 6-1 upper bottom surface 6-11 is logical light face and vertical with Z axis with bottom surface 6-12; The seamed edge of isosceles trapezoid prism 6-1 is perpendicular to the principal section of the first displacement crystal 4;

Isosceles trapezoid prism 6-1 left surface 6-13 and right flank 6-14, upper isosceles right angle prism 6-2 left surface 6-21 and right flank 6-22, lower isosceles right angle prism 6-3 left surface 6-31 and right flank 6-32 are reflecting surface;

Described the second displacement crystal 7 is rectangular parallelepiped birefringece crystal, and its logical light face is vertical with Z-direction, and the second displacement crystal 7 principal sections are parallel with the first displacement crystal 4 principal sections, and direction of optic axis is identical; The direction of optic axis of each displacement crystal is the angle theta of optical axis and o light normal direction; Described first, second displacement crystal is single axial birefringence crystal.

Light beam vertical incidence, be broken down into o light and e light after entering each displacement crystal, the deviation angle α of o light and e light two light beams meets relational expression:

$\tan \mathrm{\&alpha;}=(1-\frac{n_o^2}{n_e^2})\frac{\tan \mathrm{\&theta;}}{1+\frac{n_o^2}{n_e^2}{\tan }^2\mathrm{\&theta;}},$

In formula, n _oand n _ebe respectively the refractive index of o light and e light in displacement crystal.

The direction of optic axis of each displacement crystal is to obtain maximum o light, e light separating distance.

O light and separating distance corresponding to e light in described the first displacement crystal 4

O light and separating distance corresponding to e light in described the second displacement crystal 4

Flashlight is successively by polarization separator 1,1/2 wave plate 2, the first displacement crystal 4, quarter wave plate 5, and local oscillator light is successively by polarization separator 1,1/2 wave plate 2, phase plate 3, the first displacement crystal 4, quarter wave plate 5;

Parallel and distance is H along Z direction for input signal light and local oscillator light ₄/ 4; Input signal light and local oscillator light in the first displacement crystal with the distance d of the first displacement crystal right flank 4-1 ₁=W ₄/ 2+D ₁, input signal light in the first displacement crystal with the first displacement crystal on the distance of end face 4-2

Input signal light electric field strength E _sfor:

E wherein _sx, E _sybe respectively flashlight x component and y component, be respectively the initial phase of flashlight x component and y component electric field intensity; ω _sfor the angular frequency of flashlight, α is the energy Ratios of x in flashlight, y component, p _sfor signal light power;

Local oscillator light is linearly polarized light, and polarization direction and x axle are 45° angle, its electric field strength E _lOfor:

$E_{\mathrm{LO}}=\left[\begin{array}{c}{E}_{\mathrm{LOx}}\\ E_{\mathrm{LOy}}\end{array}\right]=\frac{1}{\sqrt{2}}\left[\begin{array}{c}{A}_{\mathrm{LO}}\\ A_{\mathrm{LO}}\end{array}\right]\exp \left({\mathrm{i\&omega;}}_{\mathrm{LO}}t\right),$

Wherein, ω _lOfor the angular frequency of local oscillator light, p _lOfor local oscillator luminous power;

Described polarization separator 1 is realized polarization separation function, and the electric field intensity of four components that flashlight and local oscillator light obtain after by polarization separator 1 is respectively flashlight x component E _sx=E ₁₁, local oscillator light x component E _lOx=E ₁₂, flashlight y component E _sy=E ₁₃with local oscillator light y component E _lOy=E ₁₄:

$E_{12}=\frac{1}{\sqrt{2}}\left[\begin{array}{c}{A}_{\mathrm{LO}}\\ 0\end{array}\right]\exp \left({\mathrm{i\&omega;}}_{\mathrm{LO}}t\right),$

$E_{14}=\frac{1}{\sqrt{2}}\left[\begin{array}{c}0\\ A_{\mathrm{LO}}\end{array}\right]\exp \left({\mathrm{i\&omega;}}_{\mathrm{LO}}t\right),$

Described 1/2 wave plate 2 is by the light beam E after polarization separation _sx, E _sy, E _lOx, E _lOypolarization state respectively rotate 45 degree, the electric field intensity of light beam after rotation

$E_{22}=\frac{1}{2}\left[\begin{array}{c}{A}_{\mathrm{LO}}\\ -A_{\mathrm{LO}}\end{array}\right]\exp \left({\mathrm{i\&omega;}}_{\mathrm{LO}}t\right),$

$E_{24}=\frac{1}{2}\left[\begin{array}{c}{A}_{\mathrm{LO}}\\ A_{\mathrm{LO}}\end{array}\right]\exp \left({\mathrm{i\&omega;}}_{\mathrm{LO}}t\right),$

Described phase plate 3 becomes circularly polarized light by local oscillator light from linearly polarized light and is used for introducing needed 90 degree phase shifts, and local oscillator light x component, y component are by the electric field strength E after quarter wave plate ₃₂, E ₃₄for:

$E_{32}=\frac{1}{2}\left[\begin{array}{c}{\mathrm{iA}}_{\mathrm{LO}}\\ -A_{\mathrm{LO}}\end{array}\right]\exp \left({\mathrm{i\&omega;}}_{\mathrm{LO}}t\right),E_{34}=\frac{1}{2}\left[\begin{array}{c}i\\ A_{\mathrm{LO}}\end{array}\right]\exp \left({\mathrm{i\&omega;}}_{\mathrm{LO}}t\right),$

The first described displacement crystal 4 is by flashlight x component E _sxbe separated into o light with e light by flashlight y component E _sybe separated into o light with e light by local oscillator light x component E _lOxbe separated into o light with e light by local oscillator light y component E _lOybe separated into o light with e light

Described quarter wave plate 5 becomes circularly polarized light by all linearly polarized lights by it, after facetted mirrors 6 reflections, passes through successively again quarter wave plate 5, the first displacement crystal 4,1/2 wave plate 2 and the second displacement crystal 7; Described quarter wave plate 5 becomes linearly polarized light by all circularly polarized lights by it, makes to pass through its light polarization 90-degree rotation twice totally before and after reflection; Described the first displacement crystal 4 is above-mentioned by what be reflected back with close bundle for E ₄₁, with close bundle for E ₄₂, with close bundle for E ₄₃, with close bundle for E ₄₄what obtain closes Shu Housi light beam E ₄₁, E ₄₂, E ₄₃, E ₄₄be followed successively by:

Described 1/2 wave plate 2 is spent all light polarization rotations 45 by it; Brilliant 7 bodies of described the second displacement are separated with y component by the x component by 1/2 wave plate 2 rear light beams, obtain eight required electric field intensity components of polarization phase diversity reception, i.e. x component quadrature output terminal electric field strength E ₅₁, E ₅₂, x component in-phase output end electric field strength E ₅₃, E ₅₄, y component quadrature output terminal electric field strength E ₅₅, E ₅₆, y component in-phase output end electric field strength E ₅₇, E ₅₈, its corresponding expression formula is followed successively by:

Obtain the power P of eight required components of polarization phase diversity reception ₅₁, P ₅₂, P ₅₃, P ₅₄, P ₅₅, P ₅₆, P ₅₇, P ₅₈be followed successively by:

Polarization, phase diversity through above-mentioned optical mixer are processed, then by after opto-electronic conversion and balance detection, corresponding x component quadrature output current I _xQ, x component homophase output current I _xI, y component quadrature output current I _yQ, y component homophase output current I _yIbe followed successively by:

The responsiveness that wherein R is photodetector.

In the present embodiment, the material of described each displacement crystal is Yttrium Orthovanadate.Described flashlight and local oscillator optical wavelength are 1550nm, and beam diameter is 0.4mm, and on this wavelength, the refractive index of Yttrium Orthovanadate is n _o=1.9447, n _e=2.1486, the direction of optic axis of each displacement crystal is θ=47.85 °.

The first displacement crystal 4 is along the length L of Z direction ₄=15mm, in the first displacement crystal, the separating distance of o light and e light is D ₁=1.4981mm; The first displacement crystal 4 is in the width W of directions X ₄=4mm; The first displacement crystal 4 is in the height H in Y-direction ₄=4mm;

Polarization separator 1 is in the width W of directions X ₁=1.5mm, polarization separator 1 is in the length L of Z direction ₁=2mm;

1/2 wave plate 2 is in the width W of directions X ₂=4mm, 1/2 wave plate 2 is in the height H of Y-direction ₂=4mm;

The length of side W of square quarter wave plate in phase plate 3 ₃=1mm;

Quarter wave plate 5 is in the width W of directions X ₅=4mm, quarter wave plate 5 is in the height H of Y-direction ₅=4mm;

The long L=2mm of the better-than-average waist right angle prism of facetted mirrors 6 6-2 seamed edge, isosceles trapezoid prism 6-1 bottom surface 6-12 is in the width W of directions X ₆=4mm, isosceles trapezoid prism 6-1 bottom surface 6-12 is in the height H of Y-direction ₆=4mm;

The second displacement crystal 7 is along the length L of Z direction ₇=10mm; The separating distance D of o light and e light in the second displacement crystal 7 ₂=0.9987mm; The second displacement crystal 7 is in the width W of directions X ₇=2.5mm, the second displacement crystal 7 is in the height H of Y-direction ₇=4mm;

Parallel and distance is 1mm along Z direction for input signal light and local oscillator light; Input signal light and local oscillator light in the first displacement crystal with the distance d of the first displacement crystal right flank 4-1 ₁=3.5mm, input signal light in the first displacement crystal with the first displacement crystal on the distance d of end face 4-2 ₂=2.5mm.

Claims (3)

1. a reflective coherent receiver optical mixer, along input path, be disposed with polarization separator (1), 1/2 wave plate (2), phase plate (3), the first displacement crystal (4), quarter wave plate (5) and facetted mirrors (6), on the reflected light path of facetted mirrors (6), be disposed with quarter wave plate (5), the first displacement crystal (4), 1/2 wave plate (2), the second displacement crystal (7), wherein 1/2 wave plate (2), the first displacement crystal (4), quarter wave plate (5) are common parts, it is characterized in that:

Described polarization separator (1) is comprised of polarization separation prism and 45 degree catoptron stacks; Described polarization separation prism forms square crystal by two blocks of identical right angled isosceles triangle birefringece crystals are bonding, the logical light face of its incident is vertical with Z-direction, described 45 degree catoptrons are right angled isosceles triangle quartz crystal, the right-angle side of its right-angle side length and right angled isosceles triangle birefringece crystal is equal in length, and the hypotenuse place reflecting surface of described 45 degree catoptrons is parallel with the parting plane of described polarization separation prism;

The logical light face of described 1/2 wave plate (2) is vertical with Z axis, and quick shaft direction and the first displacement crystal (4) principal section are 22.5 degree angles;

Described phase plate (3) is upper and lower two foursquare quarter wave plates, lays respectively at after polarization separator two of local oscillator light and goes out optical position, and quick shaft direction is all parallel with the first displacement crystal (4) principal section;

Described the first displacement crystal (4) is rectangular parallelepiped birefringece crystal, principal section and XOZ plane parallel, and logical light face is vertical with Z axis; Principal section is the optical axis of crystal, o light and the residing common plane of e light;

The logical light face of described quarter wave plate (5) is vertical with Z axis, and quick shaft direction and the first displacement crystal (4) principal section are miter angle;

Described facetted mirrors (6) is constituted by an isosceles trapezoid prism (6-1) and two identical upper isosceles right angle prisms (6-2), lower isosceles right angle prisms (6-3), the upper bottom surface (6-11) of isosceles trapezoid prism (6-1) is parallel with bottom surface (6-12), and the angle of isosceles trapezoid prism (6-1) left surface (6-13) and right flank (6-14) and bottom surface (6-12) is 45 degree; The angle of upper isosceles right angle prism (6-2) left surface (6-21) and right flank (6-22) and bottom surface (6-23) is 45 degree; The angle of lower isosceles right angle prism (6-3) left surface (6-31) and right flank (6-32) and bottom surface (6-33) is 45 degree; Upper isosceles right angle prism (6-2) bottom surface (6-23), lower isosceles right angle prism (6-3) bottom surface (6-33) are square and overlap with isosceles trapezoid prism (6-1) upper bottom surface (6-11), and the seamed edge of upper isosceles right angle prism (6-2) and lower isosceles right angle prism (6-3) is vertical with the seamed edge of isosceles trapezoid prism (6-1);

Isosceles trapezoid prism (6-1) upper bottom surface (6-11) is logical light face and vertical with Z axis with bottom surface (6-12); The seamed edge of isosceles trapezoid prism (6-1) is perpendicular to the principal section of the first displacement crystal (4);

Isosceles trapezoid prism (6-1) left surface (6-13) and right flank (6-14), upper isosceles right angle prism (6-2) left surface (6-21) and right flank (6-22), lower isosceles right angle prism (6-3) left surface (6-31) and right flank (6-32) are reflecting surface;

Described the second displacement crystal (7) is rectangular parallelepiped birefringece crystal, and its logical light face is vertical with Z-direction, and the second displacement crystal (7) principal section is parallel with the first displacement crystal (4) principal section, and direction of optic axis is identical; The direction of optic axis of each displacement crystal is the angle theta of optical axis and o light normal direction; Described first, second displacement crystal is single axial birefringence crystal, and in each displacement crystal, the refractive index of o light and e light is respectively n _oand n _e.

2. reflective coherent receiver optical mixer as claimed in claim 1, is characterized in that:

Described first, second displacement crystal is kalzit, Yttrium Orthovanadate, α phase barium metaborate or lithium niobate;

The direction of optic axis of described first, second displacement crystal

3. reflective coherent receiver optical mixer as claimed in claim 1 or 2, is characterized in that:

Described the first displacement crystal (4) is along the length of Z direction wherein Φ is the beam diameter of flashlight and local oscillator light; In the first displacement crystal (4), the separating distance of o light and e light is the first displacement crystal (4) is in the width W of directions X ₄> 2D ₁+ Φ; The first displacement crystal (4) is in the height H of Y-direction ₄: 4 Φ < H ₄< 4D ₁-2 Φ;

Described polarization separator (1) is in the width W of directions X ₁> Φ, polarization separator (1) is in the length L of Z direction ₁=H ₄/ 2;

Described 1/2 wave plate (2) is in the width W of directions X ₂=W ₄, 1/2 wave plate (2) is in the height H of Y-direction ₂=H ₄;

The length of side W of square quarter wave plate in described phase plate (3) ₃: Φ < W ₃< (H ₄/ 2-Φ);

Described quarter wave plate (5) is in the width W of directions X ₅=W ₄, quarter wave plate (5) is in the height H of Y-direction ₅=H ₄;

The long L=H of the better-than-average waist right angle prism of described facetted mirrors (6) (6-2) seamed edge ₄/ 2, isosceles trapezoid prism (6-1) bottom surface (6-12) is in the width W of directions X ₆=W ₄, isosceles trapezoid prism (6-1) bottom surface (6-12) is in the height H of Y-direction ₆=H ₄;

Described the second displacement crystal (7) is along the length of Z direction the separating distance of o light and e light in the second displacement crystal (7) the second displacement crystal (7) is in the width W of directions X ₇> D ₂+ Φ, the second displacement crystal (7) is in the height H of Y-direction ₇=H ₄;

Parallel and distance is H along Z direction for input signal light and local oscillator light ₄/ 4; Input signal light and local oscillator light in the first displacement crystal with the distance d of the first displacement crystal right flank (4-1) ₁=W ₄/ 2+D ₁, input signal light in the first displacement crystal with the first displacement crystal on the distance of end face (4-2) $d_2=\frac{{2H}_4}{8}.$