CN209170393U

CN209170393U - HVDC Modulation quantum key distribution phase decoding device and quantum key distribution system based on polarized orthogonal rotation

Info

Publication number: CN209170393U
Application number: CN201821763951.4U
Authority: CN
Inventors: 许华醒
Original assignee: China Electronics Technology Group Corp CETC
Current assignee: China Electronics Technology Group Corp CETC
Priority date: 2018-10-29
Filing date: 2018-10-29
Publication date: 2019-07-26
Anticipated expiration: 2028-10-29

Abstract

It is a kind of based on polarized orthogonal rotation HVDC Modulation quantum key distribution phase decoding device and including the system of the device.The device includes: preposition beam splitter, first phase decoder and second phase decoder, and preposition beam splitter is used to the incident beam splitting of input optical pulse all the way be two-way light pulse.First phase decoder includes the first beam splitter, the first bundling device and two the first sub-light roads, at least one the first sub-light roads include at least one first polarized orthogonal rotating device, second phase decoder includes the second beam splitter, the second bundling device and two the second sub-light roads, at least one the second sub-light roads include at least one second polarized orthogonal rotating device, and first phase decoder and/or second phase decoder have the direct current phase-modulator for carrying out direct current phase-modulation to the sub-light pulse through the sub- optic path where it.The decoding scheme of the utility model can resist polarization induction decline, suitable for there are the high speed quantum key distribution systems of environmental disturbances.

Description

Based on polarized orthogonal rotation HVDC Modulation quantum key distribution phase decoding device and Quantum key distribution system

Technical field

The utility model relates to optical transport private communication technology field more particularly to it is a kind of based on polarized orthogonal rotation it is straight Stream modulation quantum key distribution phase decoding device and the quantum key distribution system including the device.

Background technique

Quantum Secure Communication is the forward position focus field that quantum physics are combined with information science.Based on quantum key Distribution technology and one time cryptosystem principle, quantum secret communication can be in the safe transmissions of overt channel realization information.Quantum is close Key distribution can be realized based on physical principles such as quantum mechanics Heisenberg uncertainty relationship, quantum non-clone principles in user Between safely shared key, and can detecte potential eavesdropping behavior, it is contour to can be applied to national defence, government affairs, finance, electric power The field of security information transmission demand.

Currently, the encoding scheme of quantum key distribution mainly uses polarization encoder and phase code.Ground quantum key point Hair is based primarily upon fibre channel transmission, and there are the non-circular symmetrical, fiber core refractive index in section radially uneven distributions for optical fiber fabrication Equal non-idealities, and optical fiber is influenced by temperature, strain, bending etc. in the actual environment, can generate random birefringence effect. It when using polarization encoder, is influenced by optical fiber random birefringence, the quantum state of polarization encoder reaches after long-distance optical fiber transmits When receiving end, light pulse polarization state can occur to change at random, and the bit error rate is caused to increase, and result in the need for increasing correcting device, increase System complexity and cost, and stable application is difficult to realize for strong jammings situations such as aerial optical cable, road and bridge optical cables.Compared to inclined Vibration coding, the phase difference of phase code light pulse before and after is come encoded information, energy during long-distance optical fiber transmission Enough stablize keeps.However for phase encoding scheme, when interfering decoding, because transmission fiber and encoding and decoding interferometer optical fiber are two-fold There is polarization induction decline, cause decoding interference unstable in the influence penetrated.Equally, if increasing correcting device, although only It needs to rectify a deviation to a kind of polarization state, but also will increase system complexity and cost.For quantum key distribution phase code Scheme, how to carry out to stability and high efficiency interference decoding is that the heat of quantum secret communication application is carried out based on existing optical cable infrastructure Point and problem.

Utility model content

The main purpose of the utility model is that proposing a kind of HVDC Modulation quantum key point based on polarized orthogonal rotation Phase decoding device is sent out, to solve phase decoding interference caused by polarization induction declines in the application of phase code quantum key distribution Unstable problem.

To achieve the above object, the utility model provides at least following technical scheme:

1. a kind of HVDC Modulation quantum key distribution phase decoding device based on polarized orthogonal rotation, which is characterized in that The phase decoding device includes:

Preposition beam splitter is configured for the beam splitting of input optical pulse all the way of incident random polarization state being first via light Pulse and the second tunnel light pulse；

With the first phase decoder of the preposition beam splitter optical coupling, be configured for the first via light pulse into Row phase decoding；And

With the second phase decoder of the preposition beam splitter optical coupling, be configured for second tunnel light pulse into Row phase decoding,

Wherein, the first phase decoder include the first beam splitter, the first bundling device and with first beam splitter Optical coupling and two the first sub-light roads with the first bundling device optical coupling, wherein

First beam splitter is configured for the first via light pulse beam splitting being the pulse of the first sub-light of two-way；

Two first sub-light roads are configured for transmitting the first sub-light of two-way pulse respectively, and for realizing institute State the relative time delay of two-way the first sub-light pulse；

First bundling device is configured for closing two-way the first sub-light pulse into beam output,

Wherein, at least one the first polarization is included in at least one the first sub-light roads in two first sub-light roads Orthogonal rotating device, the first polarized orthogonal rotating device is configured for will be through the first sub-light pulse all the way of its transmission Two orthogonal polarisation states carry out polarized orthogonal rotation respectively so that via after the first polarized orthogonal rotating device this all the way first Each polarization state in two orthogonal polarisation states of sub-light pulse is transformed into orthogonal to that polarization state respectively,

Wherein in the first phase decoder, two first sub-light roads and optical device thereon are configured to control A polarization state in two orthogonal polarisation states of the first via light pulse is made during beam splitting to conjunction beam through described two The phase difference of the sub- optic path of item first makes two through the phase difference of two first sub- optic paths with another polarization state A phase difference differs the integral multiple of 2 π；

Wherein, the second phase decoder include the second beam splitter, the second bundling device and with second beam splitter Optical coupling and two the second sub-light roads with the second bundling device optical coupling, wherein

Second beam splitter is configured for the second tunnel light pulse beam splitting being the pulse of the second sub-light of two-way；

Two second sub-light roads are configured for transmitting the second sub-light of two-way pulse respectively, and for realizing institute State the relative time delay of two-way the second sub-light pulse；

Second bundling device is configured for closing two-way the second sub-light pulse into beam output,

Wherein, at least one the second polarization is included in at least one the second sub-light roads in two second sub-light roads Orthogonal rotating device, the second polarized orthogonal rotating device is configured for will be through the second sub-light pulse all the way of its transmission Two orthogonal polarisation states carry out polarized orthogonal rotation respectively so that via after the second polarized orthogonal rotating device this all the way second Each polarization state in two orthogonal polarisation states of sub-light pulse is transformed into orthogonal to that polarization state respectively,

Wherein in the second phase decoder, two second sub-light roads and optical device thereon are configured to control A polarization state in two orthogonal polarisation states of second tunnel light pulse is made during beam splitting to conjunction beam through described two The phase difference of the sub- optic path of item second makes two through the phase difference of two second sub- optic paths with another polarization state A phase difference differs the integral multiple of 2 π；And

Wherein the first phase decoder has the direct current phase being located at least one of described two first sub-light roads Position modulator and/or the second phase decoder have the direct current being located at least one of described two second sub-light roads Phase-modulator, the direct current phase-modulator are used for the sub-light pulse through the sub- optic path where it according to quantum key Distribution protocol carries out direct current phase-modulation.

2. the HVDC Modulation quantum key distribution phase decoding device according to scheme 1 based on polarized orthogonal rotation, It is characterized in that, two first sub-light roads and the second sub-light road are configured as polarization maintaining optical fibre optical path, two first sons Optical path and optical device thereon are further constructed to, and control a polarization eigen state of the polarization maintaining optical fibre at described two article The distance and be converted to this that first sub-light road in one sub-light road is transmitted under the polarization eigen state situation when transmitting The first distance for the distance transmitted under the orthogonal polarisation state situation of polarization eigen state is poor and the polarization eigen state is at described two The distance and converting that another the first sub-light road in first sub-light road is transmitted under the polarization eigen state situation when transmitting Second range difference for the distance transmitted under the orthogonal polarisation state situation of the polarization eigen state so that first distance difference and second away from The integral multiple of deviation difference beat length of polarization maintaining optical fiber；And/or

Two second sub-light roads and optical device thereon are further constructed to, and control one of the polarization maintaining optical fibre Polarization eigen state on a second sub-light road in two second sub-light roads when transmitting under the polarization eigen state situation The third range difference of the distance of transmission and the distance transmitted under the orthogonal polarisation state situation for being converted to the polarization eigen state and The polarization eigen state on another the second sub-light road in two second sub-light roads when transmitting in the polarization eigen state feelings 4th range difference of the distance transmitted under shape and the distance transmitted under the orthogonal polarisation state situation for being converted to the polarization eigen state, So that the integral multiple of third range difference and the 4th range difference difference beat length of polarization maintaining optical fiber.

3. based on the HVDC Modulation quantum key distribution phase decoding dress of polarized orthogonal rotation according to scheme 1 or 2 It sets, which is characterized in that

Two first sub-light roads include a first polarized orthogonal rotating device, and each first polarized orthogonal revolves Rotary device is located at the midpoint on place the first sub-light road；And/or

Two second sub-light roads include a second polarized orthogonal rotating device, and each second polarized orthogonal revolves Rotary device is located at the midpoint on place the second sub-light road.

4. the HVDC Modulation quantum key distribution phase decoding device according to scheme 1 based on polarized orthogonal rotation, It is characterized in that, the first polarized orthogonal rotating device and the second polarized orthogonal rotating device be 90 degree of Faraday rotators or Half-wave plate.

5. the HVDC Modulation quantum key distribution phase decoding device according to scheme 1 based on polarized orthogonal rotation, It is characterized in that, the phase decoding device further include:

First polarization maintaining optical fibre stretcher of any first sub-light road in two first sub-light roads, and/or First birefringent phase modulator of any first sub-light road in two first sub-light roads, first polarization-maintaining Fiber stretcher is configured for adjusting the polarization maintaining optical fibre length of the optical path where it, the first birefringent phase modulator quilt It is configured to apply different adjustable phase-modulations to two orthogonal polarisation states of the light pulse by it；And/or

Second polarization maintaining optical fibre stretcher of any second sub-light road in two second sub-light roads, and/or Second birefringent phase modulator of any second sub-light road in two second sub-light roads, second polarization-maintaining Fiber stretcher is configured for adjusting the polarization maintaining optical fibre length of the optical path where it, the second birefringent phase modulator quilt It is configured to apply different adjustable phase-modulations to two orthogonal polarisation states of the light pulse by it.

6. the HVDC Modulation quantum key distribution phase decoding device according to scheme 1 based on polarized orthogonal rotation, It is characterized in that, the direct current phase-modulator fiber stretcher or length-adjustable free space optical path or the unrelated phase of polarization Position modulator is realized；The direct current phase-modulator is configured for so that in the first phase decoder and second phase solution Made phase-modulation is relative in the first phase decoder and second phase solution in a phase decoder in code device Made phase-modulation differs 90 degree in another phase decoder in code device.

7. the HVDC Modulation quantum key distribution phase decoding device according to scheme 1 based on polarized orthogonal rotation, It is characterized in that, the first phase decoder and/or second phase decoder are using unequal arm Mach-Zender interferometer Structure；Or

The first phase decoder and/or second phase decoder use the optical path knot of unequal arm Michelson's interferometer Structure, wherein in the case where the first phase decoder uses the structure of unequal arm Michelson's interferometer, first phase The first bundling device and the first beam splitter of position decoder are same device, the first phase decoder further include:

Two the first reflecting mirrors, described two first reflecting mirrors are located at two the first sub-lights road, use respectively In the two-way the first sub-light pulse-echo that will come from first beam splitter through two first sub- optic paths Return first bundling device；With

First optical circulator, first optical circulator are located at first beam splitter front end, the first via light pulse It is input to the first port of first optical circulator and exports from the second port of first optical circulator to described first Beam splitter, the light pulse after the conjunction beam from first bundling device are input to the second port of first optical circulator simultaneously It is exported from the third port of first optical circulator；And/or

In the case where the second phase decoder uses the structure of unequal arm Michelson's interferometer, second phase The second bundling device and the second beam splitter of position decoder are same device, the second phase decoder further include:

Two the second reflecting mirrors, described two second reflecting mirrors are located at two the second sub-lights road, use respectively In the two-way the second sub-light pulse-echo that will come from second beam splitter through two second sub- optic paths Return second bundling device；With

Second optical circulator, second optical circulator are located at second beam splitter front end, second tunnel light pulse It is input to the first port of second optical circulator and exports from the second port of second optical circulator to described second Beam splitter, the light pulse after the conjunction beam from second bundling device are input to the second port of second optical circulator simultaneously It is exported from the third port of second optical circulator,

Wherein the first beam splitter of the unequal arm Michelson's interferometer or the corresponding output port of the second beam splitter it One with input port be same port.

8. the HVDC Modulation quantum key distribution phase decoding device according to scheme 7 based on polarized orthogonal rotation, It is characterized in that,

In the case where the first phase decoder uses the structure of unequal arm Michelson's interferometer, described two articles the One sub-light road separately includes the first polarized orthogonal rotating device, and the first polarized orthogonal rotating device is located at The midpoint for the interfere arm that first beam splitter and two first reflecting mirrors are constituted；And/or

In the case where the second phase decoder uses the structure of unequal arm Michelson's interferometer, described two articles the Two sub-light roads separately include the second polarized orthogonal rotating device, and the second polarized orthogonal rotating device is located at The midpoint for the interfere arm that second beam splitter and two second reflecting mirrors are constituted.

9. the HVDC Modulation quantum key distribution phase decoding device according to scheme 1 based on polarized orthogonal rotation, It is characterized in that,

Two first sub-light roads and the second sub-light road are configured as polarization and keep optical path；

Light between first beam splitter, first bundling device and first beam splitter and first bundling device The optical device of road is that polarization keeps optical device or non-birefringent optical device；And/or

Light between second beam splitter, second bundling device and second beam splitter and second bundling device The optical device of road is that polarization keeps optical device or non-birefringent optical device.

10. a kind of quantum key distribution system characterized by comprising

HVDC Modulation quantum key distribution phase based on polarized orthogonal rotation according to any one of scheme 1~9 The receiving end of the quantum key distribution system is arranged in for phase decoding in decoding apparatus；And/or

HVDC Modulation quantum key distribution phase based on polarized orthogonal rotation according to any one of scheme 1~9 The transmitting terminal of the quantum key distribution system is arranged in for phase code in decoding apparatus.

Using the embodiment of the utility model, it can be achieved that multiple advantages.For example, the utility model passes through control light pulse two The difference of the phase difference of each comfortable polarization-maintaining decoding interferometer two-arm transmission of orthogonal polarisation state, realizes random polarization state input optical pulse Stablize decoding interference, and polarized orthogonal rotating device is arranged by interferometer two-arm, is easy to real by the control of fiber lengths Now stablize decoded phase difference requirement, solves polarization induction decline in phase code quantum key distribution system and cause system can not The problem of steady operation.In addition, by receiving end by input optical pulse beam splitting be two-way light pulse after respectively to this two-way light Pulse carries out phase decoding, carries out direct current to every road light pulse during phase decoding and selects keynote system, it may be advantageous to reduce The relevant requirement of phase-modulation when base is selected to decoding, particularly with the high speed phase avoided when base is selected in decoding for High Speed System Position modulation requires.The quantum key distribution decoding scheme of the utility model can resist polarization induction decline, can be highly suitable for There are the high speed quantum key distribution application scenarios of environmental disturbances.

Detailed description of the invention

Fig. 1 is the HVDC Modulation quantum key based on polarized orthogonal rotation for one preferred embodiment of the utility model Distribute the flow chart of the phase decoding method of phase decoding device；

Fig. 2 is the HVDC Modulation quantum key distribution based on polarized orthogonal rotation of one preferred embodiment of the utility model The composed structure schematic diagram of phase decoding device；

Fig. 3 is the HVDC Modulation quantum key point based on polarized orthogonal rotation of another preferred embodiment of the utility model Send out the composed structure schematic diagram of phase decoding device；

Fig. 4 is the HVDC Modulation quantum key point based on polarized orthogonal rotation of another preferred embodiment of the utility model Send out the composed structure schematic diagram of phase decoding device.

Specific embodiment

Specifically describe the preferred embodiment of the utility model with reference to the accompanying drawing, wherein attached drawing constitutes the application one Part, and be used to illustrate the principles of the present invention together with the embodiments of the present invention.For purpose of clarity and simplification, When it may make the theme of the utility model smudgy, to the detailed of the known function and structure of device described herein Illustrating will omit.

Fig. 1 is the HVDC Modulation quantum key based on polarized orthogonal rotation for one preferred embodiment of the utility model Distribute the flow chart of the phase decoding method of phase decoding device, as shown in Figure 1, specifically includes the following steps:

Step S101: being first via light pulse and the second tunnel by the beam splitting of input optical pulse all the way of incident random polarization state Light pulse.

Specifically, incident input optical pulse is random polarization state, it is can be linear polarization, circular polarization or oval The complete polarized light of polarization is also possible to partial poolarized light or non-polarized light.

It preferably, is two-way light pulse by 50:50 beam splitting by incident input optical pulse all the way.

Step S102: respectively to after beam splitting the first via light pulse and the second tunnel light pulse according to quantum key distribution Agreement carries out phase decoding output.

As skilled in the art will understand, can be regarded as per light pulse all the way by two orthogonal polarisation states (for example, Orthogonal x-polarisation state and y-polarisation state) composition.Naturally, the two-way sub-light pulse obtained by light pulse beam splitting all the way can also be same Sample is regarded as to be made of two orthogonal polarisation states identical with the road light pulse.

Step S103: the first via light pulse and the second tunnel light pulse are carried out according to quantum key distribution agreement respectively Phase decoding can include:

For in the first via light pulse and the second tunnel light pulse per light pulse all the way,

It is the pulse of two-way sub-light by the road light pulse beam splitting；And

The two-way sub-light pulse is transmitted in two strip optical paths respectively, and relative time delay is made into the two-way sub-light pulse Beam output is closed afterwards,

Wherein, it is rotated at least one sub-light road in the two strips optical path comprising at least one polarized orthogonal Device, the polarized orthogonal rotating device are configured for distinguish through two orthogonal polarisation states of the light pulse all the way of its transmission Polarized orthogonal rotation is carried out, so that after via the polarized orthogonal rotating device, this is all the way in two orthogonal polarisation states of light pulse Each polarization state be transformed into orthogonal to that polarization state respectively, and

Wherein, a polarization state in two orthogonal polarisation states of the road light pulse is controlled in beam splitting to during closing beam Phase difference and another polarization state through the two strips optic path are during beam splitting to conjunction beam through two sub-lights The phase difference of road transmission makes the integral multiple of two 2 π of phase differences difference.

Specifically, the polarized orthogonal rotating device can be 90 degree of Faraday rotators or half-wave plate.

Step S104: respectively to the first via light pulse and the second tunnel light pulse according to quantum key distribution agreement into Phase-modulation is carried out during row phase decoding as described below: during beam splitting to conjunction beam, to the first via light arteries and veins It rushes at least one of two-way sub-light pulse that beam splitting obtains and carries out direct current phase-modulation according to quantum key distribution agreement, and/or At least one of two-way sub-light pulse obtained to the second tunnel light pulse beam splitting carries out straight according to quantum key distribution agreement Flow phase-modulation.

Here, relative time delay and phase-modulation are carried out according to the requirement and regulation of quantum key distribution agreement, are not made herein It is described in detail.

For step S103, passed through during each comfortable beam splitting to conjunction beam of two orthogonal polarisation states about light pulse all the way The phase difference of corresponding two strips optic path differs the integral multiple of 2 π, for example, it is assumed that the two orthogonal polarisation states difference For x-polarisation state and y-polarisation state, x-polarisation state is indicated in beam splitting to phase difference during closing beam through two strip optic paths For Δ x, y-polarisation state is shown as Δ y, the road Ze Gai light in beam splitting to the phase meter through two strip optic paths during closing beam A polarization state in two orthogonal polarisation states of pulse is during beam splitting to conjunction beam through the two strips optic path Phase difference differs 2 π's with another polarization state in beam splitting to the phase difference through two strips optic path during closing beam Integral multiple, in other words, through two strip optical paths during each comfortable beam splitting to conjunction beam of two orthogonal polarisation states of the road light pulse The phase difference of transmission differs the integral multiple of 2 π, can indicate are as follows:

Δ x-Δ y=2 π * m,

Wherein m is integer, can be positive integer, negative integer or zero.

It is advantageous, control a strip optical path of the polarization eigen state of the polarization maintaining optical fibre in the two strips optical path The distance transmitted under the polarization eigen state situation when upper transmission and in the orthogonal polarisation state situation for being converted to the polarization eigen state Another strip optical path that the first distance of the distance of lower transmission is poor and the polarization eigen state is in the two strips optical path uploads It the distance transmitted under the polarization eigen state situation when defeated and is passed under the orthogonal polarisation state situation for being converted to the polarization eigen state The second range difference of defeated distance, so that the integral multiple of first distance difference and second range difference difference beat length of polarization maintaining optical fiber, it can So that a polarization state in two orthogonal polarisation states of corresponding input optical pulse is described to passing through during closing beam in beam splitting The phase difference of two strip optic paths differs the integer of 2 π with another polarization state through the phase difference of the two strips optic path Times, in other words, so that through described during each comfortable beam splitting to conjunction beam of two orthogonal polarisation states of corresponding input optical pulse The phase difference of two strip optic paths differs the integral multiple of 2 π.

Specifically, it is assumed that a certain polarization eigen state of polarization maintaining optical fibre transmits in the strip optical path in the two strips optical path When the distance transmitted under the polarization eigen state situation be L1, passed under the orthogonal polarisation state situation for being converted to the polarization eigen state Defeated distance is L2, and the distance transmitted under the polarization eigen state situation when transmitting on another sub-light road is L3, is being converted to The distance transmitted under the orthogonal polarisation state situation of the polarization eigen state is L4, then

(L1-L2)-(L3-L4)=n β, in other words

(L1-L3)-(L2-L4)=n β

Wherein n is positive integer, negative integer or zero, and β is beat length of polarization maintaining optical fiber.

" beat length of polarization maintaining optical fiber " is concept well known in the art, refers to two polarization eigen states of polarization maintaining optical fibre along polarization-maintaining light Fibre transmission generates polarization maintaining optical fibre length corresponding to 2 π phase differences.

Advantageous, a polarization state in two orthogonal polarisation states for controlling the road light pulse is in beam splitting to conjunction beam Phase difference and phase difference of another polarization state through the two strips optic path in the process through the two strips optic path So that two phase differences differ the integral multiple of 2 π, comprising: the two strips optical path includes a polarized orthogonal rotating device, and Each polarized orthogonal rotating device is located at the midpoint on place sub-light road.

In a kind of possible embodiment, for every light all the way in the first via light pulse and the second tunnel light pulse Pulse: the two strip optical paths for being used for transmission the two-way sub-light pulse that the road light pulse beam splitting obtains include for the road light pulse There are birefringent optical paths for two orthogonal polarisation states, and/or with two for the road light pulse in this two strips optical path There are birefringent optical devices for orthogonal polarisation state.In this case, it controls in two orthogonal polarisation states of the road light pulse Phase difference and another polarization state of one polarization state during beam splitting to conjunction beam through the two strips optic path are through institute State the integral multiple that the phase difference of two strip optic paths makes two phase differences differ 2 π, comprising: keep the two orthogonal respectively Each of polarization state polarization state keeps polarization state constant when beam splitting is to during closing beam through two optic paths And/or keep its corresponding orthogonal polarisation state constant after the polarized orthogonal rotating device carries out polarized orthogonal rotation；And Adjustment is there are the length of birefringent optical path and/or there are the birefringent sizes of birefringent optical device, so that the two are orthogonal A polarization state in polarization state beam splitting to during closing beam through the two strips optic path phase difference and another Polarization state makes the integral multiple of two 2 π of phase differences difference through the phase difference of the two strips optic path.Optionally, this can be with Pass through following any realization: i) configuring polarization maintaining optical fibre optical path for the two strips optical path, it will be in the polarization maintaining optical fibre optical path Optical device is configured to non-birefringent optical device and/or polarization-maintaining optical device；Ii) free sky is configured by one of described two strips optical path Between optical path, configure non-birefringent optical device and/or polarization-maintaining optical device for the optical device in the two strips optical path.Herein, " polarization maintaining optical fibre optical path ", which refers to, connects the optical path to be formed using the optical path or polarization maintaining optical fibre of polarization maintaining optical fibre transmission light pulse.It is " non-double Refraction optical device " refers to the optical device for having identical refractive index for different polarization states (for example, two orthogonal polarisation states).Separately Outside, polarization keeps optical device to be alternatively referred to as polarization-maintaining optical device.

In a kind of possible realization, for every light arteries and veins all the way in the first via light pulse and the second tunnel light pulse Punching: at least one son in the two strip optical paths that the two-way sub-light pulse for obtaining to the road light pulse beam splitting is transmitted Polarization maintaining optical fibre stretcher and/or birefringent phase modulator are configured in optical path.Polarization maintaining optical fibre stretcher is suitable for adjusting where it The polarization maintaining optical fibre length of optical path.Birefringent phase modulator is suitable for applying two orthogonal polarisation states by it different adjustable Phase-modulation, thus each comfortable beam splitting of two orthogonal polarisation states that can be provided to influence and adjust the road light pulse is to closing beam During the phase difference through the two strips optic path difference.For example, birefringent phase modulator can be lithium niobate phase Position modulator is applied to the voltage of lithium columbate crystal by controlling, can to by two of the lithium niobate phase modulator just The phase-modulation for handing over polarization state to be respectively subjected to is controlled and is adjusted.As a result, birefringent phase modulator can be used for influence and Each comfortable beam splitting of two orthogonal polarisation states of the road light pulse is adjusted to closing during beam through the two strips optic path The difference of phase difference.

Carrying out direct current phase-modulation to a light pulse can be realized by multiple means, these means can include: modulation is certainly By the length perhaps length of modulation optical fiber or the unrelated phase-modulator of modulating polarization etc. of space optical path.For example, can pass through Change the length of free space optical path with motor to realize desired direct current phase-modulation.It for another example, can be by utilizing piezoelectric effect Fiber stretcher carry out the length of modulation optical fiber, be achieved in phase-modulation.In addition, phase-modulator can be suitable for voltage control The other types of system, it is orthogonal partially come two to light pulse to unrelated phase-modulator is polarized by applying suitable DC voltage Polarization state carries out identical phase-modulation, it can be achieved that desired direct current phase-modulation.In the case where direct current phase-modulation, without becoming Change the voltage for being applied to phase-modulator.

In a preferred embodiment, to the light pulse all the way in the first via light pulse and the second tunnel light pulse point Phase-modulation made by least one of two-way sub-light pulse that beam obtains with to the first via light pulse and the second road Guang Mai Phase-modulation made by least one of two-way sub-light pulse that another way light pulse beam splitting in punching obtains differs 90 degree.

A kind of HVDC Modulation quantum key distribution based on polarized orthogonal rotation of one preferred embodiment of the utility model Phase decoding device is as shown in Fig. 2, include consisting of part: preposition beam splitter 201；First beam splitter 202, the first bundling device 204 and two the first sub-light roads between them；And second beam splitter 205, the second bundling device 207 and between them two The second sub-light of item road.Be provided with the first direct current phase-modulator 203 on one of two first sub-light roads, two the second sub-light roads it The second direct current phase-modulator 206 is provided on one.It may be provided at least one first polarization on one of two first sub-light roads Orthogonal rotating device 208 may be provided at least one second polarized orthogonal rotating device 209 on one of two second sub-light roads. The first polarized orthogonal rotating device 208 or the second polarized orthogonal rotating device 209 are configured for will transmit through it one Two orthogonal polarisation states of road light pulse carry out polarized orthogonal rotation respectively, so that after via polarized orthogonal rotating device, accordingly Light pulse all the way two orthogonal polarisation states in each polarization state be transformed into orthogonal to that polarization state respectively.First beam splitting Device 202, the first bundling device 204 and two the first sub-light roads between them totally can be described as first phase decoder, and second point Beam device 205, the second bundling device 207 and two the second sub-light roads between them totally can be described as second phase decoder.First Direct current phase-modulator 203 and the second direct current phase-modulator 206 are used for the sub-light pulse through the sub- optic path where it Direct current phase-modulation is carried out according to quantum key distribution agreement.

Preferably, the first polarized orthogonal rotating device 208 and the second polarized orthogonal rotating device 209 can be 90 Spend Faraday rotator or half-wave plate.90 degree of Faraday rotators can revolve the light pulse transmitted along polarization maintaining optical fibre slow axis It goes to and is transmitted along polarization maintaining optical fibre fast axle, and/or the light pulse transmitted along polarization maintaining optical fibre fast axle is rotated to along polarization maintaining optical fibre slow axis Transmission, to realize the polarized orthogonal rotation of two orthogonal polarisation states of light pulse.For the half-wave plate, such as art technology Known to personnel, it is arranged to the fast axle or slow axis with half-wave plate in the polarization direction of one of two orthogonal polarisation states of light pulse Angle when being 45 degree, each polarization state in two orthogonal polarisation states of light pulse can be transformed into respectively by half-wave plate Orthogonal to that polarization state, to realize the polarized orthogonal rotation of light pulse.

Preposition beam splitter 201 is used to the beam splitting of input optical pulse all the way of incident random polarization state be two-way light pulse.

First phase decoder and preposition 201 optical coupling of beam splitter, for receiving the light all the way in above-mentioned two-way light pulse Pulse simultaneously carries out phase decoding to it.For convenience, this all the way light pulse be hereinafter also referred to be first via light pulse.

Second phase decoder and preposition 201 optical coupling of beam splitter, for receiving the another way in above-mentioned two-way light pulse Light pulse simultaneously carries out phase decoding to it.For convenience, which is hereinafter also referred to be the second tunnel light pulse.

First beam splitter 202 is used to first via light pulse beam splitting be the pulse of the first sub-light of two-way, respectively through two articles the One sub- optic path simultaneously is made to close beam output by the first bundling device 204 after relative time delay by this two the first sub-light roads.First direct current Phase-modulator 203 is used for the first sub-light pulse transmitted through one of two the first sub-light roads where it according to quantum key Distribution protocol carries out direct current phase-modulation.Specifically, two the first sub-light roads are used to transmit this two-way the first sub-light pulse respectively, And for realizing the relative time delay of this two-way the first sub-light pulse.It can be by adjusting the first beam splitter 202 and the first bundling device 204 Between two the first sub-light roads in any optical path physical length realize the relative time delay of two-way the first sub-light pulse.First Beam output is closed in this two-way the first sub-light pulse of bundling device 204 for that will come through two the first sub- optic paths.

Second beam splitter 205 is used to the second tunnel light pulse beam splitting be the pulse of the second sub-light of two-way, respectively through two articles the Two sub- optic paths simultaneously are made to close beam output by the second bundling device 207 after relative time delay by this two the second sub-light roads.Second direct current Phase-modulator 206 is used for the second sub-light pulse transmitted through one of two the second sub-light roads where it according to quantum key Distribution protocol carries out direct current phase-modulation.Specifically, two the second sub-light roads are used to transmit this two-way the second sub-light pulse respectively, And for realizing the relative time delay of this two-way the second sub-light pulse.It can be by adjusting the second beam splitter 205 and the second bundling device 207 Between two the second sub-light roads in any optical path physical length realize the relative time delay of two-way the second sub-light pulse.Second Beam output is closed in this two-way the second sub-light pulse of bundling device 207 for that will come through two the second sub- optic paths.

Although all having direct current phase-modulator Fig. 2 shows first phase decoder and second phase decoder, first It is possible that only one in phase decoder and second phase decoder, which has direct current phase-modulator,.In any case, Preferably, available direct current phase-modulator leads to a phase solution in first phase decoder and second phase decoder Made phase-modulation is relative to another phase decoding in first phase decoder and second phase decoder in code device Made phase-modulation differs 90 degree in device.

According to the utility model, in each phase decoder in the first and second phase decoders, two strip optical paths And optical device thereon is configured so that each comfortable beam splitting of two orthogonal polarisation states of corresponding light pulse all the way to the process for closing beam The middle phase difference through two strip optic paths differs the integral multiple of 2 π.

Preferably, as above-mentioned illustrated by method embodiment, two first sub-light roads and the second sub-light Road is configured as polarization maintaining optical fibre optical path, and two first sub-light roads and optical device thereon are further constructed to, and controls institute A polarization eigen state of polarization maintaining optical fibre is stated when transmitting on a first sub-light road in two first sub-light roads at this The distance transmitted under polarization eigen state situation and the distance transmitted under the orthogonal polarisation state situation for being converted to the polarization eigen state First distance it is poor and the polarization eigen state on another the first sub-light road in two first sub-light roads when transmitting It the distance transmitted under the polarization eigen state situation and is transmitted under the orthogonal polarisation state situation for being converted to the polarization eigen state The second range difference of distance, so that the integral multiple of first distance difference and second range difference difference beat length of polarization maintaining optical fiber, so that All the way a polarization state in two orthogonal polarisation states of input optical pulse beam splitting to during closing beam through described two articles the The phase difference of one sub- optic path and another polarization state are passed to during closing beam through two first sub-light roads in beam splitting Defeated phase difference differs the integral multiple of 2 π.And/or two second sub-light roads and optical device thereon are further configured At controlling a second sub-light Lu Shangchuan of the polarization eigen state of the polarization maintaining optical fibre in two second sub-light roads It the distance transmitted under the polarization eigen state situation when defeated and is passed under the orthogonal polarisation state situation for being converted to the polarization eigen state Another second sub-light road of the third range difference and the polarization eigen state of defeated distance in two second sub-light roads The distance transmitted under the polarization eigen state situation when upper transmission and in the orthogonal polarisation state situation for being converted to the polarization eigen state 4th range difference of the distance of lower transmission, so that the integral multiple of third range difference and the 4th range difference difference beat length of polarization maintaining optical fiber, So that a polarization state in two orthogonal polarisation states of input optical pulse is during beam splitting to conjunction beam through institute all the way State two the second sub- optic paths phase difference and another polarization state beam splitting to close beam during through described two second The phase difference of sub- optic path differs the integral multiple of 2 π.

Preferably, two first sub-light roads include a first polarized orthogonal rotating device, and each first is inclined The orthogonal rotating device that shakes is located at the midpoint on place the first sub-light road so that two of corresponding input optical pulse easy to accomplish just The difference of the phase difference through two first sub- optic paths is the whole of 2 π during handing over each comfortable beam splitting of polarization state extremely to close beam Several times.And/or two second sub-light roads include a second polarized orthogonal rotating device, and each second polarization is just Rotating device is handed over to be located at the midpoint on place the second sub-light road, so that two of corresponding input optical pulse easy to accomplish are orthogonal inclined The integral multiple that the difference of the phase difference through two second sub- optic paths is 2 π during each comfortable beam splitting to conjunction beam of polarization state.

One sub- optical path there may be birefringent or there is no birefringent, depends on the sub-light for two orthogonal polarisation states The type on road.For example, free space optical path for input optical pulse all the way two orthogonal polarisation states there is no birefringent, and protect Inclined optic fibre light path differs greatly each other for two orthogonal polarisation states usually presence of input optical pulse all the way birefringent.Separately Outside, for an optical device in optical path for two orthogonal polarisation states there may be birefringent or there is no birefringent, depending on should The type of optical device.For example, two orthogonal polarisation states of input optical pulse all the way are not present in a non-birefringent optical device It is birefringent, and a polarization-maintaining optical device differs greatly each other for two orthogonal polarisation states usually presence of input optical pulse all the way It is birefringent.

For each of the first and second phase decoders phase decoder, can optionally there be following setting:

One of two strip optical paths between beam splitter and bundling device in phase decoder are free space optical path, this two Optical device in strip optical path, including direct current phase-modulator --- it is non-birefringent optical device and/or polarization-maintaining if any Optical device.For the setting, in the case where there is polarization-maintaining optical device, polarization-maintaining optical device itself causes to be input to the phase decoder Light pulse each comfortable beam splitting of two orthogonal polarisation states to closing the phase difference difference 2 through two strip optic paths during beam The integral multiple of π.

Two strip optical paths between beam splitter and bundling device in phase decoder are polarization maintaining optical fibre optical path, this two strip Optical device in optical path, including direct current phase-modulator --- it is polarization-maintaining optical device and/or non-birefringent smooth device if any Part.

Phase decoder may also include fiber stretcher and/or birefringent phase modulator.Fiber stretcher can be located at Any sub-light road in two strip optical paths between the beam splitter and bundling device of phase decoder, where can be used for adjusting it The polarization maintaining optical fibre length on sub-light road.By adjusting polarization maintaining optical fibre length by means of fiber stretcher, it may be advantageous to be easily achieved defeated Enter during extremely closing beam to each comfortable beam splitting of two orthogonal polarisation states of the light pulse of the phase decoder through two strip optical paths The phase difference of transmission differs the integral multiple of 2 π.In addition, fiber stretcher also is used as the use of direct current phase-modulator.Birefringent phase Position modulator can be located at any sub-light road in the two strips optical path, can be used for by its two of light pulse it is orthogonal Polarization state applies different phase-modulations.It is orthogonal by two of its light pulse by controlling the birefringent phase modulator The difference for the phase-modulation that polarization state is respectively subjected to is adjustable.In this way, by utilizing birefringent phase modulator, it is convenient to shadow Through institute during each comfortable beam splitting to conjunction beam of two orthogonal polarisation states of the light pulse that sound and adjustment are input to phase decoder State the difference of the phase difference of two strip optic paths, it is easy to accomplish the integral multiple that the difference is 2 π.The birefringent phase modulator can Think previously described lithium niobate phase modulator.

Phase decoder uses the structure of unequal arm Mach-Zender interferometer, and the optical path of interferometer two-arm is (that is, phase Two strip optical paths between the beam splitter and bundling device of position decoder) use polarization maintaining optical fibre, it is assumed that and the two-arm of interferometer is wrapped respectively Containing a polarized orthogonal rotating device, it is assumed that the distance of polarized orthogonal rotating device of the beam splitter into an arm is L1, an arm In polarized orthogonal rotating device to bundling device distance be L2, polarized orthogonal rotating device of the beam splitter into another arm away from It is L4 with a distance from for the polarized orthogonal rotating device to bundling device in L3, another arm, length relation meets (L1-L2)- (L3- L4)=n β, wherein n is positive integer, negative integer or zero, and β is beat length of polarization maintaining optical fiber.In a preferred embodiment, Two polarized orthogonal rotating devices can be located at the midpoint of two-arm, that is to say that L1=L2 and L3=L4, length relation meet (L1-L2)-(L3-L4)=0.

Phase decoder uses the structure of unequal arm Michelson's interferometer.At this point, the bundling device of phase decoder with Beam splitter is same device.In the case, phase decoder further includes two reflecting mirrors, the two reflecting mirrors are located at use In in two strip optical paths of the two-way sub-light pulse that the beam splitter beam splitting of transmission phase decoder obtains, it is respectively used to that phase will be come from The two-way sub-light pulse-echo of the beam splitter of position decoder come through the two strips optic path is gone back so as to by phase decoding Device closes beam output with beam splitter for the bundling device of same device.The beam splitter and described two reflecting mirrors are constituted described dry Two arms of interferometer separately include a polarized orthogonal rotating device, it is assumed that polarized orthogonal rotating device of the beam splitter into an arm Distance be L1, the distance of a reflecting mirror of the polarized orthogonal rotating device in an arm into two reflecting mirrors is L2, point The distance of polarized orthogonal rotating device of the beam device into another arm is L3, the polarized orthogonal rotating device in another arm is to two The distance of another reflecting mirror in reflecting mirror is L4, it is contemplated that light pulse is passed through in transmission process along two-arm round-trip transmission Polarization maintaining optical fibre slow axis or the distance of fast axle transmission are 2 times of corresponding polarization maintaining optical fibre length, and length relation meets 2 (L1-L2) -2 (L3-L4)=n β, wherein n is positive integer, negative integer or zero, and β is beat length of polarization maintaining optical fiber.As described above, " polarization maintaining fiber beat It is long " refer to that polarization maintaining optical fibre corresponding to phase difference of two polarization eigen states of polarization maintaining optical fibre along 2 π of polarization maintaining optical fibre transmission generation is long Degree.

In a preferred embodiment, two polarized orthogonal rotating devices can be located at the midpoint of two-arm, namely It is L1=L2 and L3=L4, length relation meets 2 (L1-L2) -2 (L3-L4)=0.In addition, unequal arm Michelson interference One of output port of beam splitter of instrument can be used as input port, and one of output port and input port can be same in other words Single port, and phase decoder further includes optical circulator.The optical circulator can be located at the beam splitter front end of phase decoder.Come It can be inputted from the corresponding light pulse all the way of preposition beam splitter 201 from the first port of optical circulator and from the second of optical circulator Port exports the bundling device to the beam splitter of phase decoder, from phase decoder, and (beam splitter with phase decoder is same One device) conjunction beam output can be input to optical circulator second port and from the third port of optical circulator export.

For the embodiment of Fig. 2, the first beam splitter and the second beam splitter preferably use polarization-maintaining beam splitter, the first bundling device Polarization-maintaining bundling device is preferably used with the second bundling device.

A kind of HVDC Modulation quantum key point based on polarized orthogonal rotation of another preferred embodiment of the utility model Send out phase decoding device as shown in figure 3, wherein phase decoder use unequal arm Mach-Zender interferometer structure, it is described Phase decoding device includes consisting of part: preposition beam splitter 303, polarization-maintaining beam splitter 304 and 312, polarization maintaining optical fibre stretcher 306 and 314, direct current phase-modulator 308 and 316, polarization-maintaining bundling device 309 and 317 and polarized orthogonal rotating device 305, 307,313 and 315.

Input port of one of two ports 301 and 302 of side of preposition beam splitter 303 as phase decoding device. Polarization-maintaining beam splitter 304 and polarization-maintaining bundling device 309 constitute the component part of the first Mach-Zender interferometer, polarization-maintaining beam splitter 304 Two the first sub-light roads (that is, two-arm of the first Mach-Zender interferometer) between polarization-maintaining bundling device 309 are polarization maintaining optical fibre Optical path, polarization maintaining optical fibre stretcher 306 and direct current phase-modulator 308 can be inserted into the same arm of the first Mach-Zender interferometer Or it is inserted into two arms of the first Mach-Zender interferometer respectively.First Mach-Zender interferometer two-arm includes at least one A polarized orthogonal rotating device, such as a polarized orthogonal rotating device 305 and a polarized orthogonal rotating dress can be separately included Set 307.Input optical pulse is exported after the decoding of the first Mach-Zender interferometer by output port 310 or 311.

Polarization-maintaining beam splitter 312 and polarization-maintaining bundling device 317 constitute the component part of the second Mach-Zender interferometer, polarization-maintaining Two the second sub-light roads (that is, two-arm of the second Mach-Zender interferometer) between beam splitter 312 and polarization-maintaining bundling device 317 For polarization maintaining optical fibre optical path, polarization maintaining optical fibre stretcher 314 and direct current phase-modulator 316 can be inserted into the second Mach Zehnder interference The same arm of instrument or two arms for being inserted into second Mach of-Zeng Deer interferometer respectively.Second Mach-Zender interferometer two Arm includes at least one polarized orthogonal rotating device, such as can separately include a polarized orthogonal rotating device 313 and one partially Shake orthogonal rotating device 315.Input optical pulse is after the decoding of the second Mach-Zender interferometer by output port 318 or 319 Output.

When work, input port 301 or 302 of the light pulse through beam splitter 303 is beamed into two-way light arteries and veins into beam splitter 303 Punching transmission, wherein light pulse input 304 beam splitting of polarization-maintaining beam splitter is the pulse of two-way sub-light all the way, one in the two-way sub-light pulse Way light pulse modulates (wherein polarized orthogonal rotating dress through the transmission of polarized orthogonal rotating device 305 and polarization maintaining optical fibre stretcher 306 Set 305 and polarization maintaining optical fibre stretcher 306 setting sequence it is convertible, or referred to as " sequence unrelated "), another way sub-light arteries and veins Punching is transmitted through polarized orthogonal rotating device 307 and modulates 0 degree of phase (sequence is unrelated), two ways through direct current phase-modulator 308 It is exported after polarization-maintaining bundling device 309 closes beam by output port 310 or 311 after light pulse relative time delay.It is exported from beam splitter 303 It is the pulse of two-way sub-light that another way light pulse, which inputs 312 beam splitting of polarization-maintaining beam splitter, and sub-light pulse is through polarized orthogonal rotating dress all the way 313 transmission and the modulation of polarization maintaining optical fibre stretcher 314 (sequence is unrelated) are set, the pulse of another way sub-light is through polarized orthogonal rotating device 315 transmit and modulate 90 degree of phases (sequence is unrelated) through direct current phase-modulator 316, pass through after two-way sub-light pulse relative time delay Polarization-maintaining bundling device 317 is exported after closing beam by output port 318 or 319.

Preferably for the first Mach-Zender interferometer, it is assumed that polarization-maintaining beam splitter 304 and polarized orthogonal rotating device Between 305 length be L1, between polarized orthogonal rotating device 305 and polarization-maintaining bundling device 309 length be L2, polarization-maintaining beam splitter 304 Length is length between L3, polarized orthogonal rotating device 307 and polarization-maintaining bundling device 309 between polarized orthogonal rotating device 307 For L4, polarization maintaining optical fibre stretcher 306 is modulated, so that length relation meets:

(L1-L3)-(L2-L4)=n β, in other words

(L1-L2)-(L3-L4)=n β,

Wherein β is beat length of polarization maintaining optical fiber, n is integer；So that two orthogonal polarisation states of input optical pulse each comfortable The integral multiple that the difference of the phase difference of one Mach-Zender interferometer two-arm transmission is 2 π.

Preferably for the second Mach-Zender interferometer, it is assumed that polarization-maintaining beam splitter 312 and polarized orthogonal rotating device Between 313 length be L5, between polarized orthogonal rotating device 313 and polarization-maintaining bundling device 317 length be L6, polarization-maintaining beam splitter 312 Length is length between L7, polarized orthogonal rotating device 315 and polarization-maintaining bundling device 317 between polarized orthogonal rotating device 315 For L8, polarization maintaining optical fibre stretcher 314 is modulated, so that length relation meets:

(L5-L7)-(L6-L8)=m β, in other words

(L5-L6)-(L7-L8)=m β,

Wherein β is beat length of polarization maintaining optical fiber, m is integer；

So that each comfortable second Mach-Zender interferometer two-arm transmission of two orthogonal polarisation states of input optical pulse The difference of phase difference is the integral multiple of 2 π.

Direct current phase-modulator 308 and 316 is to polarize unrelated optical device.Direct current phase-modulator 308 modulates 90 degree of phases, Direct current phase-modulator 316 modulates 0 degree of phase, and the above results are unaffected.If device does not include direct current phase-modulator 308 And/or 316, realize that direct current phase-modulation function, the above results are unaffected by polarization maintaining optical fibre stretcher 306 and/or 314.

A kind of HVDC Modulation quantum key point based on polarized orthogonal rotation of another preferred embodiment of the utility model Phase decoding device is sent out as shown in figure 4, wherein phase decoder uses the structure of unequal arm Michelson's interferometer, the phase Decoding apparatus includes consisting of part: preposition beam splitter 403, polarization-maintaining beam splitter 405 and 415, is protected optical circulator 404 and 414 Inclined fiber stretcher 407 and 417, direct current phase-modulator 410 and 420, polarized orthogonal rotating device 406,409,416 and 419, And reflecting mirror 408,411,418 and 421.

Input port of one of two ports 401 and 402 of side of preposition beam splitter 403 as phase decoding device. Optical circulator 404 receives input from port A and can then export via port B, and receiving input from port B then can be defeated via port C Out.Polarization-maintaining beam splitter 405 and reflecting mirror 408,411 form the first Michelson's interferometer, polarization maintaining optical fibre stretcher 407 and direct current Phase-modulator 410 can be inserted into the same arm of the first Michelson's interferometer or be inserted into the first Michelson's interferometer respectively Two arms.An at least arm includes at least one polarized orthogonal rotating device, such as two-arm in first Michelson's interferometer two-arm It respectively may include a polarized orthogonal rotating device 406 and a polarized orthogonal rotating device 409.Input optical pulse is stepped through first It is exported after the decoding of Ke Erxun interferometer by port 413 or to be transmitted to port C through 404 port B of optical circulator defeated by port 412 Out.

Optical circulator 414 receives input from port D and can then export via port E, and receiving input from port E then can be via end Mouth F output.Polarization-maintaining beam splitter 415 and reflecting mirror 418,421 form the second Michelson's interferometer, polarization maintaining optical fibre stretcher 417 It can be inserted into the same arm of the second Michelson's interferometer with direct current phase-modulator 420 or be inserted into the second Michelson respectively and do Two arms of interferometer.An at least arm includes at least one polarized orthogonal rotating device, example in second Michelson's interferometer two-arm As two-arm can separately include a polarized orthogonal rotating device 416 and a polarized orthogonal rotating device 419.Input optical pulse warp It is exported after the decoding of second Michelson's interferometer by port 423 or is transmitted to port F by port through 414 port E of optical circulator 422 outputs.

When work, port 401 or 402 of the light pulse through beam splitter 403 is beamed into two-way light pulse into beam splitter 403 and passes Defeated, light pulse is input to 404 port A of optical circulator and exports through 404 port B of optical circulator to polarization-maintaining beam splitter 405 and divides all the way Beam is the sub- optical pulse propagation of two-way, and sub-light pulse is through the transmission of polarized orthogonal rotating device 406 and polarization maintaining optical fibre stretcher 407 all the way Reflected after modulation (sequence unrelated) by reflecting mirror 408, the pulse of another way sub-light through the transmission of polarized orthogonal rotating device 409 and It is reflected after direct current phase-modulator 410 modulates 0 degree of phase (sequence is unrelated) by reflecting mirror 411, it is reflected through phase To the two-way sub-light pulse of delay after polarization-maintaining beam splitter 405 closes beam, is exported or exported by port 413 to optical circulator 404 Port 412 is transmitted to by port C after the B of port to export.The another way light pulse exported from beam splitter 403 is input to optical circulator 414 port D and through 414 port E of optical circulator export to 415 beam splitting of polarization-maintaining beam splitter be the sub- optical pulse propagation of two-way, a way Light pulse is after the transmission of polarized orthogonal rotating device 416 and the modulation of polarization maintaining optical fibre stretcher 417 (sequence is unrelated) by reflecting mirror 418 It reflects, the pulse of another way sub-light is transmitted through polarized orthogonal rotating device 419 and modulates 90 degree through direct current phase-modulator 420 It is reflected after phase (sequence is unrelated) by reflecting mirror 421, the reflected two-way sub-light pulse through relative time delay is through polarization-maintaining After beam splitter 415 closes beam, port 422 is transmitted to by port F after being exported or exported to 414 port E of optical circulator by port 423 Output.

It is noted that one of corresponding output port of the beam splitter 405 or 415 of unequal arm Michelson's interferometer (example Such as the port of beam splitter 405 being connected with the port B of circulator 404 or the port E with circulator 414 of beam splitter 415 The port being connected) it is also possible to the input port of beam splitter, so one of the output port of unequal arm Michelson's interferometer It can be same port with input port.

Preferably, it is assumed that length is L1 between polarization-maintaining beam splitter 405 and polarized orthogonal rotating device 406, polarized orthogonal revolves Length is L2 between rotary device 406 and reflecting mirror 408, length is between polarization-maintaining beam splitter 405 and polarized orthogonal rotating device 409 Length is L4 between L3, polarized orthogonal rotating device 409 and reflecting mirror 411, polarization maintaining optical fibre stretcher 407 is modulated, so that length Relationship meets:

2 (L1-L3) -2 (L2-L4)=n β, or

2 (L1-L2) -2 (L3-L4)=n β

Wherein β is beat length of polarization maintaining optical fiber, n is integer；

So that the phase of each comfortable first Michelson's interferometer two-arm transmission of two orthogonal polarisation states of input optical pulse The difference of potential difference is the integral multiple of 2 π.

Preferably, it is assumed that length is L5 between polarization-maintaining beam splitter 415 and polarized orthogonal rotating device 416, polarized orthogonal revolves Length is L6 between rotary device 416 and reflecting mirror 418, length is between polarization-maintaining beam splitter 415 and polarized orthogonal rotating device 419 Length is L8 between L7, polarized orthogonal rotating device 419 and reflecting mirror 421, polarization maintaining optical fibre stretcher 417 is modulated, so that length Relationship meets:

2 (L5-L7) -2 (L6-L8)=m β, or

2 (L5-L6) -2 (L7-L8)=m β

So that the phase of each comfortable second Michelson's interferometer two-arm transmission of two orthogonal polarisation states of input optical pulse The difference of potential difference is the integral multiple of 2 π.

Direct current phase-modulator 410 and 420 is to polarize unrelated device.Direct current phase-modulator 410 modulates 90 degree of phases, Direct current phase-modulator 420 modulates 0 degree of phase, and the above results are unaffected.If phase decoding device does not include direct current phase tune Device 410 and/or 420 processed realizes direct current phase-modulation function by polarization maintaining optical fibre stretcher 407 and/or 417, and the above results are not It is impacted.

Herein, term " beam splitter " and " bundling device " are used interchangeably, and beam splitter is also referred to as and as bundling device, instead ?.

In another aspect, the utility model also provides a kind of quantum key distribution system, the quantum key distribution system packet Include the above-mentioned direct current based on polarized orthogonal rotation that the receiving end of the quantum key distribution system is set for phase decoding Quantum key distribution phase decoding device is modulated, and/or the transmitting terminal including the quantum key distribution system is arranged in is used for The above-mentioned HVDC Modulation quantum key distribution phase decoding device based on polarized orthogonal rotation of phase code.

In general, environmental disturbances cause communicating pair transmission fiber and the generation of encoding and decoding interferometer optical fiber birefringent, lead to light Pulse polarization state when reaching receiving end decoding interference changes at random, so that decoding interference has polarization induction decline, influence amount Sub- secret signalling job stability.The utility model can be realized two orthogonal polarisation states of light pulse simultaneously in output end Mouth effectively interference output, is equivalent to and carries out polarization diversity processing to two orthogonal polarisation states, can effectively solve to polarize induction decline Caused interference decodes instability problem, the immune stable phase angle decoding of environmental disturbances is realized, without using polarization beam apparatus Two polarization states are decoded respectively with two interferometers, in addition also eliminate the needs to correction.In addition, the utility model Polarized orthogonal rotating device is set by interferometer two-arm, is easy to stablize decoded phase difference by the control realization of fiber lengths It is required that solve the problems, such as in phase code quantum key distribution system polarization induction decline cause system can not steady operation, this Outside by being that two-way light pulse carries out phase decoding respectively by input optical pulse beam splitting, direct current is carried out to every road light pulse and selects keynote System avoids High Speed System decoding and high-speed phase modulation when base is selected to require.

It should be able to be the technology hand reaching predetermined purpose and being taken to the utility model by the explanation of specific embodiment Section and effect have more deeply and it is specific understand, however appended diagram is only to provide reference and description and is used, and is not used to pair The utility model limits.

Although being described in detail by example embodiment, preceding description be all in all respects it is illustrative rather than It is restrictive.It should be appreciated that can be designed that range of a number of other remodeling with variant without departing from example embodiment, these Both fall within the protection scope of the utility model.Therefore, the protection scope of the utility model should be determined by the appended claims.

Claims

1. a kind of HVDC Modulation quantum key distribution phase decoding device based on polarized orthogonal rotation, which is characterized in that described Phase decoding device includes:

Preposition beam splitter is configured for the beam splitting of input optical pulse all the way of incident random polarization state being first via light pulse With the second tunnel light pulse；

With the first phase decoder of the preposition beam splitter optical coupling, it is configured for carrying out phase to the first via light pulse Position decoding；And

With the second phase decoder of the preposition beam splitter optical coupling, it is configured for carrying out phase to second tunnel light pulse Position decoding,

Wherein, the first phase decoder include the first beam splitter, the first bundling device and with the first beam splitter optocoupler Merging and two the first sub-light roads with the first bundling device optical coupling, wherein

Two first sub-light roads are configured for transmitting the first sub-light of two-way pulse respectively, and for realizing described two The relative time delay of road the first sub-light pulse；

It wherein, include at least one first polarized orthogonal in at least one the first sub-light roads in two first sub-light roads Rotating device, the first polarized orthogonal rotating device are configured for two through the first sub-light pulse all the way of its transmission Orthogonal polarisation state carries out polarized orthogonal rotation respectively, so that via first sub-light all the way after the first polarized orthogonal rotating device Each polarization state in two orthogonal polarisation states of pulse is transformed into orthogonal to that polarization state respectively,

Wherein in the first phase decoder, two first sub-light roads and optical device thereon are configured to control institute State a polarization state in two orthogonal polarisation states of first via light pulse beam splitting to during closing beam through described two articles the The phase difference of one sub- optic path makes two phases through the phase difference of two first sub- optic paths with another polarization state Potential difference differs the integral multiple of 2 π；

Wherein, the second phase decoder include the second beam splitter, the second bundling device and with the second beam splitter optocoupler Merging and two the second sub-light roads with the second bundling device optical coupling, wherein

Two second sub-light roads are configured for transmitting the second sub-light of two-way pulse respectively, and for realizing described two The relative time delay of road the second sub-light pulse；

It wherein, include at least one second polarized orthogonal in at least one the second sub-light roads in two second sub-light roads Rotating device, the second polarized orthogonal rotating device are configured for two through the second sub-light pulse all the way of its transmission Orthogonal polarisation state carries out polarized orthogonal rotation respectively, so that via second sub-light all the way after the second polarized orthogonal rotating device Each polarization state in two orthogonal polarisation states of pulse is transformed into orthogonal to that polarization state respectively,

Wherein in the second phase decoder, two second sub-light roads and optical device thereon are configured to control institute State a polarization state in two orthogonal polarisation states of the second tunnel light pulse beam splitting to during closing beam through described two articles the The phase difference of two sub- optic paths makes two phases through the phase difference of two second sub- optic paths with another polarization state Potential difference differs the integral multiple of 2 π；And

Wherein the first phase decoder has the direct current phase tune being located at least one of described two first sub-light roads Device processed and/or the second phase decoder have the direct current phase being located at least one of described two second sub-light roads Modulator, the direct current phase-modulator are used for the sub-light pulse through the sub- optic path where it according to quantum key distribution Agreement carries out direct current phase-modulation.

2. the HVDC Modulation quantum key distribution phase decoding device according to claim 1 based on polarized orthogonal rotation, It is characterized in that, two first sub-light roads and the second sub-light road are configured as polarization maintaining optical fibre optical path, two first sons Optical path and optical device thereon are further constructed to, and control a polarization eigen state of the polarization maintaining optical fibre at described two article The distance and be converted to this that first sub-light road in one sub-light road is transmitted under the polarization eigen state situation when transmitting The first distance for the distance transmitted under the orthogonal polarisation state situation of polarization eigen state is poor and the polarization eigen state is at described two The distance and converting that another the first sub-light road in first sub-light road is transmitted under the polarization eigen state situation when transmitting Second range difference for the distance transmitted under the orthogonal polarisation state situation of the polarization eigen state so that first distance difference and second away from The integral multiple of deviation difference beat length of polarization maintaining optical fiber；And/or

Two second sub-light roads and optical device thereon are further constructed to, and one for controlling the polarization maintaining optical fibre is intrinsic Polarization state is transmitted under the polarization eigen state situation when transmitting on a second sub-light road in two second sub-light roads Distance and the distance transmitted under the orthogonal polarisation state situation for being converted to the polarization eigen state third range difference and this Sign polarization state on another the second sub-light road in two second sub-light roads when transmitting under the polarization eigen state situation 4th range difference of the distance of transmission and the distance transmitted under the orthogonal polarisation state situation for being converted to the polarization eigen state, so that The integral multiple of third range difference and the 4th range difference difference beat length of polarization maintaining optical fiber.

3. the HVDC Modulation quantum key distribution phase decoding dress according to claim 1 or 2 based on polarized orthogonal rotation It sets, which is characterized in that

Two first sub-light roads include a first polarized orthogonal rotating device, and each first polarized orthogonal rotating dress Setting in the midpoint on place the first sub-light road；And/or

Two second sub-light roads include a second polarized orthogonal rotating device, and each second polarized orthogonal rotating dress Setting in the midpoint on place the second sub-light road.

4. the HVDC Modulation quantum key distribution phase decoding device according to claim 1 based on polarized orthogonal rotation, It is characterized in that, the first polarized orthogonal rotating device and the second polarized orthogonal rotating device be 90 degree of Faraday rotators or Half-wave plate.

5. the HVDC Modulation quantum key distribution phase decoding device according to claim 1 based on polarized orthogonal rotation, It is characterized in that, the phase decoding device further include:

First polarization maintaining optical fibre stretcher of any first sub-light road in two first sub-light roads, and/or be located at First birefringent phase modulator of any first sub-light road in two first sub-light roads, first polarization maintaining optical fibre Stretcher is configured for adjusting the polarization maintaining optical fibre length of the optical path where it, and the first birefringent phase modulator is configured Apply different adjustable phase-modulations for two orthogonal polarisation states to the light pulse by it；And/or

Second polarization maintaining optical fibre stretcher of any second sub-light road in two second sub-light roads, and/or be located at Second birefringent phase modulator of any second sub-light road in two second sub-light roads, second polarization maintaining optical fibre Stretcher is configured for adjusting the polarization maintaining optical fibre length of the optical path where it, and the second birefringent phase modulator is configured Apply different adjustable phase-modulations for two orthogonal polarisation states to the light pulse by it.

6. the HVDC Modulation quantum key distribution phase decoding device according to claim 1 based on polarized orthogonal rotation, It is characterized in that, the direct current phase-modulator fiber stretcher or length-adjustable free space optical path or the unrelated phase of polarization Position modulator is realized；The direct current phase-modulator is configured for so that in the first phase decoder and second phase solution Made phase-modulation is relative in the first phase decoder and second phase solution in a phase decoder in code device Made phase-modulation differs 90 degree in another phase decoder in code device.

7. the HVDC Modulation quantum key distribution phase decoding device according to claim 1 based on polarized orthogonal rotation, It is characterized in that, the first phase decoder and/or second phase decoder are using unequal arm Mach-Zender interferometer Structure；Or

The first phase decoder and/or second phase decoder use the light channel structure of unequal arm Michelson's interferometer, Wherein in the case where the first phase decoder uses the structure of unequal arm Michelson's interferometer, the first phase solution The first bundling device and the first beam splitter of code device are same device, the first phase decoder further include:

Two the first reflecting mirrors, described two first reflecting mirrors are located at two first sub-lights road, be respectively used to by Institute is gone back in the two-way the first sub-light pulse-echo come through two first sub- optic paths from first beam splitter State the first bundling device；With

First optical circulator, first optical circulator are located at first beam splitter front end, the first via light pulse input To first optical circulator first port and export from the second port of first optical circulator to first beam splitting Device, the light pulse after the conjunction beam from first bundling device are input to the second port of first optical circulator and from institutes State the third port output of the first optical circulator；And/or

In the case where the second phase decoder uses the structure of unequal arm Michelson's interferometer, the second phase solution The second bundling device and the second beam splitter of code device are same device, the second phase decoder further include:

Two the second reflecting mirrors, described two second reflecting mirrors are located at two second sub-lights road, be respectively used to by Institute is gone back in the two-way the second sub-light pulse-echo come through two second sub- optic paths from second beam splitter State the second bundling device；With

Second optical circulator, second optical circulator are located at second beam splitter front end, second tunnel light pulse input To second optical circulator first port and export from the second port of second optical circulator to second beam splitting Device, the light pulse after the conjunction beam from second bundling device are input to the second port of second optical circulator and from institutes The third port output of the second optical circulator is stated,

Wherein one of the first beam splitter of the unequal arm Michelson's interferometer or the corresponding output port of the second beam splitter with Input port is same port.

8. the HVDC Modulation quantum key distribution phase decoding device according to claim 7 based on polarized orthogonal rotation, It is characterized in that,

In the case where the first phase decoder uses the structure of unequal arm Michelson's interferometer, two first sons Optical path separately includes the first polarized orthogonal rotating device, and the first polarized orthogonal rotating device is located at described The midpoint for the interfere arm that first beam splitter and two first reflecting mirrors are constituted；And/or

In the case where the second phase decoder uses the structure of unequal arm Michelson's interferometer, two second sons Optical path separately includes the second polarized orthogonal rotating device, and the second polarized orthogonal rotating device is located at described The midpoint for the interfere arm that second beam splitter and two second reflecting mirrors are constituted.

9. the HVDC Modulation quantum key distribution phase decoding device according to claim 1 based on polarized orthogonal rotation, It is characterized in that,

Between first beam splitter, first bundling device and first beam splitter and first bundling device in optical path Optical device be that polarization keeps optical device or non-birefringent optical device；And/or

Between second beam splitter, second bundling device and second beam splitter and second bundling device in optical path Optical device be that polarization keeps optical device or non-birefringent optical device.

10. a kind of quantum key distribution system characterized by comprising

HVDC Modulation quantum key distribution phase based on polarized orthogonal rotation described according to claim 1~any one of 9 The receiving end of the quantum key distribution system is arranged in for phase decoding in decoding apparatus；And/or

HVDC Modulation quantum key distribution phase based on polarized orthogonal rotation described according to claim 1~any one of 9 The transmitting terminal of the quantum key distribution system is arranged in for phase code in decoding apparatus.