241 results about "Optical attenuator" patented technology

The invention relates to the technical field of optical fiber monitoring and maintenance, and discloses an optical fiber monitoring method, device and equipment, a storage medium and a computer program product, and the method comprises the steps: enabling pulse light of a preset period to be coupled into a to-be-detected low-loss optical fiber based on an optical fiber amplifier and a variable optical attenuator, and generating a backward scattering light signal; converting the backward scattering light signal into an electric pulse signal by using a single-photon detector, and counting the electric pulse signal by using a preset period as a period through a synchronous clock to obtain a counting result; adjusting the power of the variable optical attenuator according to a counting result, and drawing a target signal curve of the to-be-measured low-loss optical fiber based on an adjustment result; and analyzing the target signal curve to obtain a monitoring result of the to-be-measured low-loss optical fiber. The power is dynamically adjusted in different measurement sections, and the multi-section measurement results are superposed, so that the dynamic range of the single-photon optical time domain reflectometer is remarkably expanded, and the loss and dead pixels of the low-loss optical fiber can be reflected more comprehensively and accurately.

The invention relates to the technical field of communication, and discloses an intelligent diagnosis and rapid recovery method, system and device for optical path faults and a medium. The method comprises the following steps: carrying out grading processing on a data set to obtain optical path fault grade data, carrying out amplifier power adjustment through segmented gain compensation to obtain an optical power adjustment instruction, carrying out optical power compensation through an adjustable optical attenuator to obtain an optical path balance parameter, and carrying out optical power distribution equalization through power gradient calculation to obtain optical path fault grade data. Comprising inter-node power difference calculation and node power correction, power control data is obtained, finally, parameter correction is carried out through stability evaluation, power fluctuation range verification and system margin calculation are carried out, and an optical path regulation and control scheme is obtained. According to the invention, the rapid diagnosis and automatic recovery of the optical path fault are realized, the fault recovery time is improved from an hour level to a minute level, and the stability and reliability of the optical path power are ensured at the same time.

The invention discloses a laser radar echo signal simulator performance parameter testing method and device, and belongs to the field of photoelectric information. The system comprises a simulation distance related parameter measuring device, a working wavelength measuring device, a view field and distortion measuring device, an output power related parameter measuring device, a scanning speed and frame frequency and waveform similarity measuring device, an angular resolution measuring device and a simulator position adjusting device. The view field and distortion testing device is composed of a camera, an adjusting frame and a hemispherical guide rail. The scanning speed and frame frequency measuring device is composed of a focusing lens, two photoelectric detectors and an oscilloscope. The output power related parameter measuring device is composed of a focusing lens and a power meter. The working wavelength measuring device is composed of a focusing lens, an optical attenuator and a wavemeter. The placing position of the simulator on the platform is preset in advance through the simulator position adjusting device, and the simulator is sent to a specified testing position by driving the adjusting frame and the simulator to slide on the guide rail.

The utility model relates to the technical field of optical fiber communication, and discloses a polarization equalization transmitting assembly based on a coherent light silicon optical chip, which adopts a second optical splitter with an adjustable splitting ratio to split input continuous light and equalizes output light power of two paths of coherent light of X polarized light and Y polarized light. The two paths of coherent light of X polarized light and Y polarized light can be pre-adjusted only by adjusting the splitting ratio of the second optical splitter, optical power balance is achieved, high-speed electro-optical modulators in the two paths of coherent light do not need to be adjusted, the high-speed electro-optical modulators can be kept in the optimal state, an adjustable optical attenuator does not need to be additionally arranged in the two paths of coherent light, and the optical power balance is achieved. The utility model has the effects of improving the output power of the transmitting assembly, reducing the self power consumption of the transmitting assembly and improving the utilization efficiency of the high-speed photoelectric driver, and is more suitable for a small-sized packaged coherent optical module based on a coherent optical silicon optical chip.

The invention provides a high-parallelism test method of an optical comprehensive test platform, relates to the field of active optical testing, and aims to realize parallel testing of multiple tested objects or multiple test items through N independent test channels, avoid waiting time of traditional serial testing, and effectively improve manufacturing efficiency by combining the high-parallelism characteristic of the platform. Dynamic resource scheduling distributes tasks based on channel resource states monitored in real time, resource idling is avoided, the characteristic of high integration of a platform is matched, multiple modules share the platform, cost is effectively shared, the overall utilization rate of equipment is improved, modules such as optical power meters and variable optical attenuators integrated in all channels in a hardware architecture support hot plugging, and the overall performance of the equipment is improved. And the task analysis algorithm can flexibly map test items, adapt to requirements of different tested objects, conform to the advantages that the platform is matched as needed and easy to expand, can protect investment and adapt to dynamic changes of a test scene, and a distributed data acquisition mechanism synchronously acquires data of each channel and provides support for generating a reliable test report.

The invention provides a reference light polarization multiplexing TF-QKD device and a coding method, and relates to the technical field of quantum communication. A light source emitted by a single-wavelength laser is subjected to time division multiplexing modulation through a phase modulator, an intensity modulator and a polarization modulator to obtain a strong phase reference light pulse, a weak phase reference light pulse and a quantum signal light pulse; after being attenuated by the optical attenuator, the signals are sent to a detection end through an optical fiber line; after light pulses of an Alice end and a Bob end received by a detection end pass through respective links, the light pulses are modulated by polarization controllers of respective light paths and then enter a light interference module for interference, the interfered light is divided into two beams, and the two beams respectively enter a first polarization beam splitter and a second polarization beam splitter for polarization; the light split by each polarization beam splitter respectively enters two avalanche detectors for detection, and the detection result is sent to a synchronous counter to ensure that the pulse arrival time of the Alice end is consistent with the pulse arrival time of the Bob end.

The invention discloses an electrically-controlled variable optical attenuator based on a multistage wedge-shaped liquid crystal box and an attenuation control method, the attenuator comprises a laser, the laser provides an incident light signal, the divergent incident light signal is converted into a collimated parallel light beam through a collimator, the collimated parallel light beam is subjected to deflection modulation through a multistage wedge-shaped liquid crystal box module, and the modulated light beam is converted into a modulated light beam; the multi-channel liquid crystal controller is coupled to the output optical fiber through the optical fiber coupler, and generates and outputs driving voltage signals capable of being independently adjusted to the N-stage wedge-shaped liquid crystal box module, so that each wedge-shaped liquid crystal box in the multi-stage wedge-shaped liquid crystal box module is independently controlled; the control method comprises the steps of receiving a target instruction, querying a system-level relationship, distributing a deflection task, querying a device-level relationship, outputting a driving signal and performing closed-loop feedback correction. According to the invention, a large attenuation range is obtained, and at the same time, millisecond-level and even sub-millisecond-level rapid response is realized; the precision, the linearity and the usability of attenuation control are improved, and the control complexity is reduced.

Silicon Photonics is a candidate technology for adding integrated optics functionality, either passive or active optical waveguides) to integrated circuits by leveraging the economies of scale of the CMOS microelectronics industry and using materials for the waveguide core such as silicon nitride (SiXNY) and silicon oxynitride (SiOXN1-X) for example. Microelectromechanical systems (MEMS) provide for movable platforms relative to the substrate allowing additional functionality to be added to a silicon circuit but also Silicon Photonics. Accordingly, by combining “fixed” waveguides formed upon the substrate with “movable” waveguides formed upon one or more movable platforms the inventors have established a series of Integrated Optics MEMS (IO-MEMS) based on Silicon Photonics. Such IO-MEMS include optical switches, optical attenuators, optical gates, optical switch matrices, configurable wavelength division multiplexer / demultiplexer devices, etc. exploiting both platforms and deformable beams.

The present application provides a laser generation circuit and an erbium-doped fiber amplifier, relating to the field of optical communication technologies. The jitter signal generation circuit includes: a jitter signal module, an analog signal module, and a clock signal module; the first input end of the jitter signal module is connected to the output end of the analog signal module, the control end of the jitter signal module is connected to the output end of the clock signal module, and the output end of the jitter signal module is used to output a jitter signal. By connecting the jitter signal module to the analog signal module and the clock signal module respectively, the present application can adjust the amplitude of the analog signal output by the analog signal module to achieve the adjustment of the amplitude of the jitter signal, and can adjust the frequency of the clock signal output by the clock signal module to complete the adjustment of the frequency of the jitter signal, so as to be compatible with lasers provided by multiple manufacturers, without adding optical attenuation devices at the output end of the laser, and effectively reducing the cost of preparing the EDFA.

The present invention discloses a quantum random number generator chip and design method. The chip includes: an optical chip, a transimpedance amplifier chip, and a microcontroller chip connected in sequence, wherein: the optical chip includes a continuous laser, an optical beam splitter, a first optical attenuator, a second optical attenuator, a first photodetector, and a second photodetector; the microcontroller chip includes a first digital-to-analog converter, a second digital-to-analog converter, an analog-to-digital converter, and a processor; the transimpedance amplifier chip includes a transimpedance amplifier; wherein the optical chip, the transimpedance amplifier chip, and the microcontroller chip are packaged to obtain a quantum random number generator chip. The present invention packages the optical chip and the microcontroller chip into a single chip through a systematic packaging method, significantly reducing the size of the quantum random number system, greatly improving the stability of the system and structure, while reducing power consumption and cost, and expanding the scope and application scenarios.

The invention relates to a power industry Ethernet switch optical port test system, method, device and equipment, a storage medium and a program product, and relates to the technical field of optical fiber communication. The system can improve the power industry Ethernet switch optical port test efficiency. The system comprises a test environment control module, a network tester, a variable optical attenuator and a switch to be tested. The test environment control module configures the network tester, the variable optical attenuator and the switch to be tested according to the configuration information; the network tester generates a network test message under the target test case, and records a receiving and sending statistical result of the network test message; the adjustable optical attenuator records and displays the adjusted optical attenuation parameters; the to-be-tested switch realizes a switch optical port function under the target test case, and collects an optical power value in an optical port test process; and the test environment control module summarizes and analyzes the receiving and transmitting statistical result, the optical attenuation parameter and the optical power value, and outputs a test result information set of the target test case.

The invention relates to the technical field of optical fiber sensing, and discloses a distributed optical fiber temperature sensing system based on photon counting and a measurement method, which can remarkably improve the sensing distance, the spatial resolution and the spatial positioning precision. According to the scheme, the method comprises the following steps: aiming at different segments of a sensing optical fiber, controlling the attenuation amount of a variable optical attenuator, and carrying out detection and time-dependent single photon counting on backscattered light from different segments on the sensing optical fiber by utilizing a single photon avalanche diode and a time-dependent single photon counter, and temperature distribution information of the sensing optical fiber is demodulated based on a time correlation single photon counting result.

The invention provides a C + L wave band optical fiber amplification module and an optical fiber laser. The C + L wave band optical fiber amplification module comprises a first bidirectional pumping unit, a gain flattening filter, a variable optical attenuator and a second bidirectional pumping unit, a first gain optical fiber of the first bidirectional pumping unit adopts a three-section splicing structure formed by sequentially welding a first bismuth-doped optical fiber, an erbium-doped optical fiber and a second bismuth-doped optical fiber along a signal transmission direction, and a second gain optical fiber of the second bidirectional pumping unit is a bismuth-erbium co-doped optical fiber; wherein the first bidirectional pumping unit is used for performing primary amplification on C + L wave band seed light to generate first signal light; and the second bidirectional pumping unit is used for performing secondary amplification on the adjusted first signal light to generate second signal light. According to the invention, low-noise, high-gain and high-flatness C + L wave band amplification signals can be output.

The invention discloses a displacement measurement method and system based on orbital angular momentum light beam conjugate interference, and the method comprises the steps: enabling linearly polarized light emitted by a laser to pass through an optical attenuator, a light beam expander, a quarter-wave plate and a vortex wave plate to form a light beam with orbital angular momentum, and enabling the light beam to pass through a beam splitter to be divided into a reference light beam and a measurement light beam. A measurement light beam is vertically incident on a reflection grating, and the mth-order diffraction light is incident on a first cube-corner prism and is reflected back to a diffraction grating to be subjected to secondary diffraction. And after the reference beam passes through the second cube-corner prism, the topological charge symbol of the reference beam is changed by the Dove prism. The reference light beam and the measurement light beam generate conjugate interference at the beam splitter prism, a petal-shaped interference pattern collected by the CCD is demodulated, and in-plane and out-of-plane two-dimensional displacement of the grating is calculated. The system has the characteristics of simple and compact structure, strong anti-interference capability, high precision and the like, and can be widely applied to the fields of high-end equipment manufacturing, semiconductor industry, precision metering and the like.

The invention provides a self-calibration high-strength optical fiber hydrophone based on an end face reflection principle, and relates to the technical field of hydrophones. Comprising the steps that a laser light source emits a first laser beam, and an optical fiber isolator suppresses reflection and outputs a second laser beam. And the optical fiber variable optical attenuator adjusts the incident power and outputs a third laser beam. The 1 * 2 optical fiber coupler splits the laser beam into a fourth laser beam and a fifth laser beam, and the first photoelectric detector monitors power. The optical fiber circulator transmits the fifth laser beam to the optical fiber sensing module, generates reflected light and transmits the reflected light to the second photoelectric detector, and the second photoelectric detector converts the reflected light into a voltage signal. The data acquisition card acquires the signals, the signal demodulation processing unit calculates sound pressure sensitivity according to a mapping relation formula of the voltage signals and sound pressure, and the standard voltage module provides standard voltage for the data acquisition card. The problem that in the prior art, a high-strength hydrophone cannot be repeatedly used and cannot be self-calibrated after being damaged is solved.

An optical module includes an optical connector port, a plurality of variable optical attenuators, a first polarization controller, and an output port. The optical connector port connects to an optical port on a line card and receives a plurality of input optical signals from the line card when the optical connector port is connected to the optical port on the line card. The plurality of variable optical attenuators produce a plurality of attenuated optical signals based on the plurality of input optical signals. The first polarization controller produces a plurality of output optical signals based on the plurality of attenuated optical signals. The output port outputs the plurality of output optical signals.

The application provides a semiconductor laser reservoir pool computing device based on silicon-based micro-resonant cavity optical feedback, and belongs to the technical field of photonic neuromorphic computing. Laser output by a driving laser is modulated by a phase modulator, and then is injected into a response semiconductor laser through a feedback cavity incoupler and a circulator; the output end of the response semiconductor laser is connected to an optical circulator in sequence through a second variable optical attenuator, a polarization controller, a silicon-based micro-resonator and a first variable optical attenuator, so as to form a silicon-based micro-resonator optical feedback loop; the output end of the feedback cavity incoupler is connected to a broadband photodetector, which is used to collect reservoir pool output signals; the phase modulator is loaded with a modulation signal containing an input signal and a random mask, so as to realize input layer signal coding. The application realizes the improvement of overall computing performance.

The utility model relates to the technical field of laser application, in particular to a laser frequency stabilization device based on an etalon frequency measurement technology, which comprises a laser emission unit, a frequency detection unit, a frequency stabilization laser output end and a master control adjusting unit, the frequency detection unit comprises an optical splitter, an optical attenuator, a first photoelectric detector, an etalon and a second photoelectric detector. An etalon in the frequency detection unit is used as a frequency reference, an optical attenuator is arranged to reduce temperature rise and improve precision, a first photoelectric detector and a second photoelectric detector are used to provide a frequency measurement error signal and a reference signal, and the master control adjustment unit is used to carry out analysis and calculation according to the error measurement signal and the reference signal. And the laser emitting unit adjusts the laser frequency according to the adjusting signal, so that the frequency stabilization adjustment of the laser is realized.

The invention discloses a virtual simulation teaching system based on SDH (Synchronous Digital Hierarchy) equipment. The virtual simulation teaching system comprises mixed reality head display equipment, an SDH equipment simulation device and a data service device, the SDH equipment simulation device is used for constructing an SDH equipment simulation model, an optical power meter simulation model and an optical attenuator simulation model; the SDH equipment simulation device is further used for transmitting the SDH equipment simulation model, the optical power meter simulation model and the optical attenuator simulation model to mixed reality head display equipment, and the mixed reality head display equipment is used for displaying a virtual SDH equipment simulation model, a virtual optical power meter simulation model and a virtual optical attenuator simulation model; the data service device is used for providing a video tutorial of an SDH equipment simulation model principle, a video tutorial of alarm processing and a document for the mixed reality head-mounted display equipment; according to the invention, the problem of insufficient precision of the simulation model of the virtual SDH equipment is solved, interaction with the simulation model of the virtual SDH equipment is realized, and the practical operation ability of students is improved.

The invention provides a control method of a tin-lead perovskite photoelectric detector for near-infrared beacon light detection, and relates to the technical field of intelligent control, and the method comprises the steps: enabling an amplified electric signal to be coupled with a DC component through a bias T-shaped device, and generating a drive signal; driving an 850nm laser to emit near-infrared beacon light by using the driving signal; adjusting the optical power of the near-infrared beacon light through an optical attenuator; a tin-lead perovskite photoelectric detector array is adopted to receive the near-infrared beacon light adjusted by an optical attenuator, and the component of an optical active layer of the detector is FA < 0.7 > MA < 0.3 > Pb < 0.5 > Sn < 0.5 > I < 3 > and is modified by glycinamide hydrochloride; carrying out secondary amplification processing on the electric signal output by the detector, and sampling the signal after secondary amplification through an oscilloscope; and performing digital signal processing based on the sampling result, and calculating the bit error rate of the beacon optical signal. According to the invention, the signal transmission efficiency and the spectrum utilization rate are effectively improved.

The application discloses a kind of based on functional echo wall mode optical microbottle cavity Full light tuning controllable optical comb generation method. Including 1550nm narrow line width continuous wave laser, single-mode optical fiber, erbium-doped fiber amplifier, polarization controller, optical isolator, functional microbottle cavity-fiber taper coupling system, optical attenuator, optical spectrum analyzer and 1550nm power adjustable laser. The unique axial characteristics of echo wall mode microbottle cavity are used, the free spectral range of microcavity is reduced, the axial mode microcavity optical frequency comb with small free spectral range is generated, and based on full light tuning method, functional microbottle cavity is prepared, and the axial mode microcavity optical frequency comb generated is tuned by photo-thermal material titanium dioxide, and significant spectral range tuning is realized. The application solves the limitation that WGM microcavity optical frequency comb cannot be effectively tuned due to large free spectral range, and helps the practical application in the field of microcavity optical frequency comb optical communication, optical frequency synthesis and the like.

The invention relates to an integrated variable optical attenuator. In some implementations, an electro-optical device includes a multimode interferometer (MMI) variable optical attenuator (VOA) and a control component, the MMI VOA including: an input for receiving an optical beam; an output section for outputting the light beam; and an optical waveguide for coupling the input to the output, wherein the optical waveguide is configured to self-image the light beam within the optical waveguide; the control assembly is used for applying forward voltage to the two ends of the MMI VOA so as to control attenuation of the MMI VOA.

A system and method for generating ultra-short pulses intended to be inserted into a ring laser with a regulator of a pulsed signal of a certain intensity, the system includes an optical attenuator that allows the intensity of the pulsed signal to be adjusted at the input of an optical guide section, and a distributed amplification device inserted in the optical guide that make it possible to manage the power of the signal therein, so that it propagates as solitons or as self-similar pulses without suffering unwanted distortions despite the increase in the length of the laser cavity, increasing the power of the pulsed signal and making it possible to exceed the usual power limits of this type of laser.

A coherent transmitter (100, 200) for use in a time division multiple access (TDMA) system is operated in multiple states to enable coherent burst transmission. In an OFF state, the transmitter (100, 200) generates a dummy laser output (fd) from either a dummy laser (102) or an active laser (52) tuned to a dummy frequency different from an active frequency (fa), thereby maintaining thermal and bias stability without adding excess power on an upstream channel (22). In an ON state, the active laser (52) produces an active laser output (fa) that is modulated by a quad-parallel Mach-Zehnder (QPMZ) modulator (60) to transmit data. A thermoelectric cooler (TEC) (58) stabilizes laser temperatures, and a variable optical attenuator (VOA) (54) controls output power. The transmitter (100, 200) is suitable for an optical network unit (ONU) (14) in a passive optical network (PON) (10) communicating with an optical line terminal (OLT) (12).

The application relates to the technical field of laser heterodyne atmospheric remote sensing, and discloses a laser heterodyne atmospheric remote sensing device and method applied to a ship, the device comprising a sun tracking module, a heterodyne light path module, a signal processing module and a computer device, wherein the sun tracking module comprises a sun tracking meter, a photoelectric detector and an optical switch, the heterodyne light path module comprises a laser, an optical attenuator, an optical fiber combiner and a photoelectric detector; the signal processing module comprises a radio frequency amplifier, a radio frequency filter, a power detector, a lock-in amplifier and a data collector. The laser heterodyne atmospheric remote sensing device applied to the ship can reduce the precision requirement of a sun tracking meter for laser heterodyne detection, and realizes spectral detection under the condition that the probability of the alignment precision being within the range of 0.1 degrees is greater than 50%.

A fiber laser device (1) is provided with: a first excitation light source (12) capable of emitting first excitation light; a first amplification optical fiber (11) to which an active element that absorbs the first excitation light is added, and which amplifies and emits the light of the first wavelength; a second amplification optical fiber (21) to which an active element that absorbs the light of the first wavelength and is the same as the active element added to the first amplification optical fiber (11) is added, and which amplifies and emits the light of the second wavelength; beam combiners (31), (32); and a light attenuation unit (60) that is provided on an optical path between the beam combiners (31, 32) and the first amplification optical fiber (11), transmits light from the first amplification optical fiber (11), and suppresses the transmission of light from the beam combiners (31, 32).

The invention discloses an ultra-wideband weak signal detection method and system based on all-optical oscillation and phase-amplitude conversion. The method comprises the steps that spontaneous radiation light generated by an erbium-doped optical fiber amplifier is used as an optical carrier; modulating a weak radio frequency signal to be measured received by an antenna to the optical carrier through an optical modulator to form a modulated optical signal; the modulated optical signal is injected into an all-optical oscillation circuit composed of double loops, the all-optical oscillation circuit generates multimode optical oscillation by adjusting an optical attenuator, and the all-optical oscillation circuit comprises a double-loop interference structure; performing phase-amplitude conversion by adjusting the delay difference of the two light paths in the double loops to form an equivalent microwave photon filter so as to select and amplify the modulated light signal corresponding to the radio frequency signal of the set frequency band; and converting the selected and amplified modulated optical signal into an electric signal, and performing spectral analysis to detect the weak radio frequency signal to be detected.

The invention provides a laser power stability control device and method based on a Rydberg atom antenna. The laser power stability control device comprises a variable optical attenuator, a PID control module, a half slide, an optical splitter, a sampling mirror and a photoelectric detector. The variable optical attenuator adjusts the attenuation degree of a received external laser signal, and then outputs the adjusted laser signal to the optical splitter after passing through the half-wave plate through the optical fiber; after the optical splitter splits the received laser signal, one beam is output to the atomic gas chamber, and the other beam is output to the photoelectric detector; the photoelectric detector converts the received laser signal into a light intensity electric signal and outputs the light intensity electric signal to the PID control module; and the PID control module performs PID algorithm adjustment according to the light intensity preset data information, and feeds back the digital control signal carrying the control quantity to the variable optical attenuator. The technical problem that under the condition that long-distance optical fiber transmission exists between the laser power stabilizing device and the atomic gas chamber, it is difficult to maintain the stability of the laser power input into the atomic gas chamber is solved.

The invention discloses a photoelectric chip with power attenuation regulation and control and real-time monitoring functions. The photoelectric chip comprises a coupling waveguide, a connecting waveguide, a light beam splitting structure and a variable optical attenuator, an optical signal enters the chip through the input coupling waveguide and is transmitted to the optical beam splitting structure through the first connecting waveguide, the optical beam splitting structure divides the optical signal into a monitoring signal and a main transmission signal, and the monitoring signal is transmitted to the first variable optical attenuator through the optical beam splitting structure and the second connecting waveguide in sequence and then is connected to the photoelectric detection system through the monitoring output coupling waveguide. The main transmission signal is transmitted to the second variable optical attenuator through the optical beam splitting structure and the third connection waveguide in sequence, and then is transmitted back to the original optical fiber link through the main signal back-transmission coupling waveguide. The chip disclosed by the invention can be prepared on a large scale by adopting a standard micro-nano process, is low in coupling loss and high in compatibility, can be customized on a single chip or in an array manner, is accurate in monitoring and convenient to install, and can be widely applied to real-time monitoring and attenuation regulation and control of links in the fields of optical fiber communication, optical sensing and the like.

This invention discloses an integrated quantum key distribution device and method, which serves as both a transmitter and a receiver. As a transmitter, an optical injection locking device generates a group of optical pulses, which, after passing through an optical attenuator, are input to an unequal-arm Mach-Zehnder interferometer to obtain the quantum states of the corresponding basis vectors, and then input to a quantum channel. As a receiver, quantum states are received from the quantum channel. For Z-based quantum states, the output is sent to a third single-photon detector for decoding after passing through an optical beamsplitter; for X-based or Y-based quantum states, the output is sent to the unequal-arm Mach-Zehnder interferometer after passing through an optical beamsplitter, and then to a first and second single-photon detector for decoding. This invention eliminates the need for external modulation, enabling quantum state preparation and measurement within a single device using only one interferometer. This reduces the complexity of the quantum key distribution system, improves its compactness, and facilitates practical application.