211 results about "Intensity modulator" patented technology

The invention discloses a photon-assisted radar frequency shift interference and intermittent sampling forwarding interference integrated signal generation method, and relates to the technical field of microwave photon and radar countermeasure. The method is shown in a figure 1 in the specification and is realized based on a laser device (LD), an arbitrary waveform generator (AWG), a dual-drive Mach-Zehnder modulator (DDMZM), an intensity modulator (IM) and a photoelectric detector (PD). According to the method, by adjusting the period of sawtooth waves, the duty ratio of rectangular pulse signals and the sampling period, generation of interference signals integrating various frequency shift interferences and intermittent sampling and forwarding interferences can be achieved. According to the invention, two simple modulators are adopted, and complex bias voltage and polarization state control is not needed; a digital radio frequency memory is not adopted, analog-to-digital and digital-to-analog conversion is not needed, the real-time performance is good, and parameter tuning is flexible; an electric domain frequency dependent device is not adopted, interference signals with the broadband of more than 1 GHz and the wave band of more than Ku can be generated, and the device is suitable for an electronic countermeasure system with the broadband of more than 1 GHz and the wave band of more than Ku in the future.

The invention discloses a continuous variable quantum key distribution method, device and system, and belongs to the field of wireless communication. Firstly, a sending end generates continuous light pulses for discrete coding, a one-dimensional discrete modulation signal is generated, quantum signal light is generated through an attenuator, and the quantum signal light is coupled to a quantum channel for transmission. Then, a receiving end adopts a homodyne detector to measure the regular component of the quantum signal in a self-calibration manner; and after a local measurement base direction and a phase drift angle introduced by a dynamic compensation quantum channel are adjusted in real time, a covariance matrix is calculated and input into a post-processing module, the code rate of the system is further calculated, and a security key is generated by using a protocol between a receiving end and a transmitting end. According to the device, the intensity modulator is connected between the laser and the attenuator, so that one-dimensional discrete modulation is realized, and dependence on a phase reference signal is avoided. According to the system, a traditional phase locking module is removed, an asymmetric phase space coding mechanism is adopted, dependence on a phase reference signal is eliminated, and the safety and stability of the system are improved.

The invention discloses an optical computing array based on micro-ring resonators without a free spectral range, which comprises an on-chip wavelength division multiplexing beam splitting array, an on-chip intensity modulation array, two groups of on-chip wavelength division multiplexing beam combining arrays and an on-chip balance detector, the on-chip wavelength division multiplexing beam splitting array and the on-chip wavelength division multiplexing beam combining array are respectively composed of a group of multiple FSR-free MRRs which share the same bus optical waveguide, each resonator corresponds to an independent wavelength channel, and the on-chip intensity modulator array is composed of a plurality of groups of on-chip MZI modulator arrays. According to the optical calculation array implementation method, independent control and coding calculation of different wavelength channels in a broadband wavelength range are realized by utilizing the single harmonic peak characteristic of the FSR-free MRR array and the wide-spectrum intensity modulation function of the MZI unit, the limitation of a free spectrum range on the optical calculation wavelength channel is eliminated, the higher wavelength parallelism is achieved, and the optical calculation array implementation method has the advantages of being simple in structure and convenient to implement. And therefore, the calculation scale is remarkably improved.

The invention provides a frequency measurement device based on an optical frequency comb and cyclic frequency shift. The frequency measurement device comprises a laser, an optical beam splitter, an electro-optic intensity modulator, an optical cyclic frequency shift loop, an optical frequency comb generation unit, an optical beam combiner, a multichannel optical filter, a multichannel photoelectric detector, a multichannel low-pass filter and a multichannel acquisition processing unit. According to the device, broadband high-precision frequency measurement is realized by adopting a method of combining cyclic frequency shift with Fourier transform, an optical frequency comb is adopted as a local oscillation light source, sub-band division of a radio frequency spectrum is realized by combining a multi-channel optical filter, parallel frequency measurement of each sub-band can be realized, the cycle index of a frequency shift loop is reduced, the cycle time of the loop is shortened, and the measurement efficiency is improved. Noise accumulation caused by multiple cycles is reduced, and the signal-to-noise ratio and the dynamic range of radio frequency signal frequency measurement detection are improved, so that the frequency measurement requirements of broadband high precision, high signal-to-noise ratio, high dynamic and quick response are met.

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 optical fiber laser phased array self-adaptive optical system based on an integrated optical chip. The optical fiber laser phased array self-adaptive optical system comprises a self-adaptive optical fiber coupler array, the integrated optical chip, an optical fiber splitter, a photoelectric detector, a control platform and a high-voltage amplifier. The integrated optical chip comprises an optical fiber coupling interface, a waveguide, a phase shifter, a Mach-Zehnder intensity modulator and the like. The adaptive optical fiber coupler array couples incident light to the optical fiber array, and corrects tilt aberration based on an optimization control algorithm to realize efficient adaptive coupling of spatial light to optical fibers; the sub-beams enter an integrated optical chip through an optical fiber coupling interface, phase and intensity modulation is performed on the sub-beams in the optical chip based on an optimization control algorithm, and co-phase synthesis output of the beams is realized; the output light is divided into two paths by the optical fiber splitter, one path is connected with the photoelectric detector for control, and the other path is connected with the application end. Based on light path reciprocity, the system has a transmitting or receiving and transmitting integrated function, and has important application prospects in the fields of space optical communication, laser energy transfer and the like.

The invention relates to a monolithic integrated wide-narrow passband reconfigurable electro-optical modulator, and belongs to the field of electro-optical modulators. The optical modulator comprises a substrate, and a tunable optical splitter, a dual-output intensity modulator, a phase modulator, a tunable optical attenuator, a first optical combiner and a second optical combiner which are integrated on the substrate. Wherein the input end of the tunable optical splitter receives an input optical signal, and the output end of the tunable optical splitter is respectively connected with the input ends of the dual-output intensity modulator and the phase modulator; the first output end of the dual-output intensity modulator is connected with the input end of the second optical combiner, and the second output end of the dual-output intensity modulator is connected with the input end of the tunable optical attenuator; the output end of the phase modulator and the output end of the tunable optical attenuator are both connected with the input end of the first optical combiner, and the output end of the first optical combiner is connected with the input end of the second optical combiner. And the output end of the second optical combiner outputs a modulated optical signal.

The invention discloses a device for realizing in-situ tuning of photo-induced dipole-dipole interaction between particles. The device comprises a light source module, a light trap modulation module, a vacuum cavity module, a detection module and a control module, the light source module provides reference light for the detection module while providing high-power laser for the light trap modulation module; the optical trap modulation module is used for modulating the laser beam to generate double beams with phase coherence; the vacuum cavity module provides a vacuum environment for the optical suspension nanoparticles; the detection module is used for detecting the movement of the nanoparticles; the control module is used for analyzing and processing the detection signal, inverting the interaction intensity of the particles, generating a control signal, controlling an intensity modulator in the light trap modulation module to apply alternating-current high-frequency modulation to a light beam, and realizing control on oscillation amplitudes of the two nanoparticles by utilizing feedback control; therefore, in-situ tuning and control of photo-induced dipole-dipole interaction among the nanoparticles are realized. According to the invention, stable suspension of double nanoparticles under high vacuum can be provided.

The invention discloses a silicon-based integrated device for synchronously measuring microwave frequency and an angle of arrival and a measuring method. The light source is used for emitting light carriers to the input end of the double-parallel Mach-Zehnder photoelectric intensity modulator, and the two radar antennas arranged at intervals receive microwave signals to be measured and send the microwave signals to the double-parallel Mach-Zehnder photoelectric intensity modulator. The double-parallel Mach-Zehnder photoelectric intensity modulator loads a microwave signal to be measured onto an optical carrier to generate two paths of optical carrier microwave signals and sends the two paths of optical carrier microwave signals to the first instantaneous frequency measurement unit and the second instantaneous frequency measurement unit and the arrival angle measurement unit, and rough frequency measurement, fine frequency measurement and arrival angle measurement of the optical carrier microwave signals are carried out respectively. A single structure is adopted, synchronous and efficient measurement of the frequency and the arrival angle of a radar microwave signal is achieved, the detection efficiency is remarkably improved, the technical problem of simultaneous measurement of the microwave frequency and the arrival angle with on-chip integration, high precision, light weight, low power consumption and powerful functions is solved, the practicability of the system is improved, and the application range of the system is widened.

An optical transmission apparatus includes: a distributing unit which distributes a laser beam based on a first oscillation frequency; a phase modulator which generates, using the laser beam based on the first oscillation frequency, a phase-modulated signal that is an optical signal phase-modulated in accordance with a modulated signal; a multiplexing unit which multiplexes a laser beam based on a second oscillation frequency and the phase-modulated signal; a detecting unit which generates a frequency-modulated signal by performing detection processing on a result of multiplexing of the laser beam based on the second oscillation frequency and the phase-modulated signal; and an intensity modulator which generates, using the laser beam based on the first oscillation frequency, an optical signal intensity-modulated in accordance with the frequency-modulated signal.

The invention relates to an adjustable signal source with low phase noise, comprising:an optical-microwave phase detector (BOMPD) which comprises:an intensity modulator (BIM) having an optical signal input, a modulation input (1), a first output (O1), and a second output (O2),a first photodiode (PD1) which can be irradiated by light from the first output (O1) during operation,a second photodiode (PD2) which can be irradiated by light from the second output (O2) during operation,wherein the first photodiode (PD1) and the second photodiode (PD2) are connected in series in a biased manner during operation,wherein a tap for a tap signal is arranged between the first photodiode (PD1) and the second photodiode (PD2),further comprising a controllable DC power source (N4),wherein an offset current is can be set at the tap during operation by means of the first DC power source (N4), whereby the symmetry of the optical-microwave phase detector is canceled by an offset current during operation,wherein the tap is routed to a low-pass filter with any potential offset current,wherein the low-pass filtered tap signal is provided to an adjustable oscillator (OSZ).

The invention discloses a dual-polarization IQ modulation continuous variable quantum key distribution chip system device and method, and the device achieves the intensity difference between a quantum signal and a pilot signal through the addition of an intensity modulator, can effectively reduce the requirements of a dual-polarization IQ modulation CV-QKD chip for the modulation bit width of a DAC, and improves the system performance. The problem that an existing dual-polarization IQ modulation local oscillator CV-QKD system is poor in modulation performance is effectively solved.

The invention discloses a device and a method for testing frequency domain characteristics of a high-speed optoelectronic device. The device comprises a laser, a sawtooth wave generator, a signal source, an acousto-optic modulator, an electro-optic intensity modulator, a low-frequency photoelectric detector, a frequency spectrograph and a computer. An electro-optic intensity modulator is driven through a sawtooth wave modulation technology, and frequency-shifted and non-frequency-shifted optical carriers and frequency-shifted and non-frequency-shifted radio frequency optical sidebands are synchronously generated in an optical path in combination with radio frequency signal modulation. And after the signal is subjected to beat frequency processing by the photoelectric detector, the power of the frequency shift signal in different working states is measured by the frequency spectrograph, so that the frequency domain characteristic parameters of the photoelectric device to be measured are obtained. The method is based on sawtooth wave modulation and an amplitude comparison method, frequency domain response characteristics of a single / dual-drive electro-optic intensity modulator, dual-parallel electro-optic intensity modulation and a photoelectric detector can be accurately represented, the test method is simple, and dependence on a high-frequency test instrument is effectively reduced.

The invention discloses a phase coding optoelectronic oscillator with an adjustable duty ratio and an implementation method thereof, and relates to the technical field of photoelectricity. The optoelectronic oscillator comprises a laser, a Mach-Zehnder modulator, a single-mode fiber, a photoelectric detector, an electric amplifier, an electric band-pass filter and an electric power divider which are connected in sequence; a direct current port of the intensity modulator is connected with the function generator, one path of the electric power divider serves as output, and the other path is connected with a radio frequency port of the intensity modulator; the output voltage of the preset function generator jumps between the two linear bias points and the minimum bias point of the Mach-Zehnder modulator, so that the direct output of the phase-coded microwave signal with the adjustable duty ratio is realized. According to the invention, the coherence of the phase coding microwave signal is good, the phase noise is low, the duty ratio is adjustable, the coding flexibility is high, the structure is simple, and the equipment cost is low.

The invention provides a wide-tuning high-power microwave signal generation device and method, and the device comprises a laser, an acousto-optic modulator, a signal generator, an electro-optic intensity modulator, an arbitrary waveform generator, an all-fiber amplifier, a Pockels box, a solid-state amplifier, a photoconductive semiconductor switch, and a bias voltage source. The acousto-optic modulator is respectively connected with the laser, the signal generator and the electro-optic intensity modulator, the electro-optic intensity modulator is respectively connected with the acousto-optic modulator, the arbitrary waveform generator and the all-fiber amplifier, and the Pockels box is respectively connected with the all-fiber amplifier and the solid-state amplifier. And the photoconductive semiconductor switch is respectively connected with the solid-state amplifier and the bias voltage source. The invention provides a wide-tuning high-power microwave signal generation device and method, which are used for solving the problems that the frequency of a microwave signal generated by an existing vacuum electronic device is difficult to change quickly and the size between the vacuum electronic devices is heavy.

The invention relates to the field of signal frequency detection in microwave photonics, and discloses a broadband instantaneous frequency measurement receiving system based on Brillouin spectrum compression, which utilizes a dual-tone pump optical carrier signal carried on an intensity modulator and an optical filter to generate a single Brillouin pump source regulated and controlled by unknown radio frequency. A stimulated Brillouin structure narrowed by an optical fiber ring cavity and a single-pumping reference source subjected to phase shift beat frequency, a signal in a 45GHz range can be compressed to a bandwidth of 2.5 MHz, and meanwhile, an original signal can be subjected to optical domain down-conversion processing by a reference source signal, so that a low-frequency signal easy to process electronically is obtained; besides, a double-fiber annular cavity design is adopted, the line width of the Brillouin resonant laser is further compressed through mode matching of interference of light waves in the cavity, test precision reduction caused by frequency spectrum compression is made up, the resolution ratio can reach + / -2.2 MHz, and finally the Brillouin broadband instantaneous frequency measurement receiving technology is achieved.

The invention belongs to the field of laser, and discloses an on-chip tunable femtosecond light source based on an integrated electro-optical frequency comb, which comprises an intensity modulator (9), a first phase modulator (10) and a second phase modulator (11) which are integrated on the same chip and are connected in sequence, the three paths of radio frequency driving signals respectively provide radio frequency driving signals for the intensity modulator, the first phase modulator and the second phase modulator; the intensity modulator performs intensity modulation on the wavelength-tunable continuous optical signal to generate a flat-topped optical pulse sequence; the first phase modulator and the second phase modulator are used for performing quadratic phase modulation on the flat-topped optical pulse sequence to generate a broadband electro-optical frequency comb; the dispersion optical fiber is used for carrying out pulse compression on the electro-optical frequency comb so as to generate femtosecond optical pulses. Compared with an existing femtosecond pulse light source generation system, the femtosecond pulse light source generation system has the advantages of being simple in structure, high in integration level, tunable in pulse width and repetition frequency, low in cost and the like.

The application discloses a microwave photon filter and a control method thereof, and belongs to the field of optical fiber communication. The filter comprises an optical ring cavity, a tunable laser source, an electro-optic intensity modulator, a photoelectric detector and an electric vector network analyzer. The first input end of the electro-optic intensity modulator is connected with the output end of the tunable laser source, the second input port of the electro-optic intensity modulator is connected with the output end of the electric vector network analyzer, and the output end of the electro-optic intensity modulator is connected with the input end of an optical circulator in the optical ring cavity. The output end of the optical circulator in the optical ring cavity is connected with the input end of the photoelectric detector, and the output end of the photoelectric detector is connected with the input end of the electric vector network analyzer. The application can overcome the problem that the device parameters cannot be adjusted after the structure of the microwave photon filter is determined.

The application discloses an optical multiplier system for processing high-speed data flow and a method thereof, and belongs to the technical field of semiconductors, comprising a stibonium quantum well laser, an intensity modulator, a phase modulator, a balanced homodyne detector and an oscilloscope; the stibonium quantum well laser is used as a light source, light signals output by the stibonium quantum well laser are evenly divided into two light beams by a Y-type beam splitter, and the two light beams are defined as x-vector light beams and y-vector light beams respectively; the two light beams sequentially pass through the intensity modulator and the phase modulator to complete real number and complex number coding; after the two light beams are coupled by a beam splitter / coupler, the two light beams are input to the balanced homodyne detector for detection, and the photocurrent output by the balanced homodyne detector is calculated to obtain a differential current, the differential current is collected and displayed in real time by the oscilloscope, and the differential current is the vector point multiplication operation result corresponding to the two vector light beams. The application has the characteristics of low cost, low energy consumption, high speed, expandability and the like.

The invention discloses an optical frequency comb generation device and method based on a 3 * 3 optical fiber coupler, and the device comprises a single-frequency microwave source, a phase shifter, a continuous wave laser, an intensity modulator, a phase modulator, a first connection optical fiber part, and a second connection optical fiber part. The microwave signal output end is connected with the intensity modulator or the phase modulator; the continuous wave laser comprises a laser signal output end, and the laser signal output end is connected with the intensity modulator; the intensity modulator and the phase modulator are connected with the input end of the non-linear optical annular mirror through the first connecting optical fiber part, the output end of the non-linear optical annular mirror is connected with the second connecting optical fiber part, and the non-linear optical annular mirror comprises a 3 * 3 optical fiber coupler and a non-linear optical fiber which are coupled; a 3 * 3 optical fiber coupler is adopted to form a nonlinear optical annular mirror, ultra-short pulse shaping is achieved through the interference effect between two paths of reverse transmission light fields, continuous wave background noise and pulse base side lobes are effectively eliminated, and through the design of an optical fiber coupling mode and a loop port connection mode and the selection of an input end and an output end, ultra-short pulse shaping is achieved. And the nonlinear chirp part of the pulse waveform is greatly inhibited, and the linear characteristic of the nonlinear chirp part is kept, so that the ultra-wideband optical frequency comb light source with remarkable spectral balance is realized in the high nonlinear parameter mixing process.

This invention relates to the fields of optical fiber communication and microwave photonics. Existing tunable dual-passband microwave photonic filters suffer from poor passband stability and cannot meet practical application requirements. This invention provides a narrow-band tunable dual-passband microwave photonic filter using a Brillouin fiber laser. It generates dual-tone pump light to excite the Brillouin using a tunable laser source and an intensity modulator. Combined with a Brillouin fiber oscillator and a cascaded Fabry-Perot cavity, the Brillouin gain spectrum is narrowed to the kHz level. Simultaneously, the different periodic resonant frequencies of the two ring cavities effectively suppress side modes, filtering out the desired frequency band signal. Furthermore, by synchronously tuning the center frequencies of the two passbands of the filter by changing the pump light wavelength, and simultaneously controlling the output frequency of the signal generator, the frequency interval between the two passbands is changed, ultimately realizing a narrow-linewidth tunable dual-passband microwave photonic filter.

The application discloses a Fourier domain mode locked laser based on a laser dynamic establishment process and a control method, and comprises a ring laser cavity which is composed of an optical amplifier, a first isolator, a second isolator, an adjustable filter, a delay optical fiber, a coupler and a polarization controller or an optical amplifier, a first isolator, a second isolator, an adjustable filter, a delay optical fiber, a coupler, an intensity modulator and a polarization controller. When the dispersion amount in the ring laser cavity exceeds the bandwidth range of the adjustable filter, the optical amplifier or the intensity modulator is controlled to restart, so that the laser signal is restarted instead of the signal in the continuous gain cavity, the residual dispersion in the cavity is resisted, high coherent swept laser output is realized, any dispersion compensation technology is not needed, the scheme is simple, the requirements of the devices used for the laser are low, environment control technology is not needed, the scheme has strong robustness, the cost is reduced, and the Fourier domain mode locked laser can be applied to any waveband.

The invention provides an optical time-frequency analysis method based on a tunable optical filter, and relates to the technical field of optical fiber communication time-frequency analysis, and the method comprises the steps: transmitting an optical carrier wave through a time lens generation unit, modulating the optical carrier wave, and obtaining a chirp optical carrier wave as a time lens; the wavelength of the optical carrier is adjusted, so that the focal length of the time lens is equal to the equivalent dispersion value of the tunable optical filter, and the period of the time lens is equal to the reciprocal of the full width at half maximum of the tunable optical filter; an original input signal is modulated to a time lens by using an electro-optical intensity modulator to obtain a chirp optical signal; processing the chirp optical signal by using a tunable optical filter; under the combined action of the tunable optical filter and the time lens, completing frequency-time mapping processing on an original input signal to obtain an optical signal after frequency-time mapping; and finally, the optical signal is converted into an electric signal, and then the electric signal is converted into frequency spectrum information which can be observed in real time. According to the invention, the real-time performance and compatibility of spectrum analysis of non-stationary signals can be improved.

A dispersion gating-based atmospheric composition measurement laser radar. The atmospheric composition measurement laser radar stretches a femtosecond laser into a broad pulse laser in a time domain by means of dispersion. A femtosecond spectrum is mapped into the broadened laser pulse due to the group velocity dispersion, and then is subjected to time domain gating by means of an intensity modulator (22, 26) for completing the selection of a laser of a preset wavelength. The laser wavelength scanning is achieved by adjusting the delay of an electrical drive signal of the intensity modulator (22, 26). An absorption spectrum of a specific atmospheric composition is obtained by means of laser wavelength scanning so as to measure the concentration of the atmospheric gas composition. The atmospheric composition measurement laser radar can precisely perform free gating on the wavelength where the laser emits, and has high precision in selecting the wavelength. Scanning and detection of a plurality of gases can be achieved by adjusting the center wavelength of a filter.

The application discloses a kind of intensity modulation polarization encoding quantum key distribution systems based on sagnac ring, including communication end Bob and communication end Alice, the communication end Bob and communication end Alice are connected by optical fiber channel;The laser in the communication end Bob generates optical signal into optical isolator and exports linearly polarized signal parallel to cat eye direction into first polarization maintaining beam splitter;First polarization maintaining beam splitter exports linearly polarized signal parallel to cat eye direction into communication end Alice;Communication end Alice divides the linearly polarized signal parallel to cat eye direction into first linearly polarized signal and second linearly polarized signal with equal intensity and carries out intensity modulation, and finally polarized state signal is output into communication end Bob by the beam combination superposition of third polarization beam splitter after being combined, first single-photon detector to fourth single-photon detector in communication end Bob carries out measurement.The polarization encoding and quantum state modulation of signal are realized by one intensity modulator in the application, and the equipment cost of QKD is reduced.

The invention discloses an airborne orbital angular momentum MDI-QKD link building device, which comprises a transmitting end Alice, a transmitting end Bob and a receiving end Charlie, and is characterized in that the transmitting end Alice comprises a first laser, a first spatial light modulator SLM1, a first attenuator ATT, a first reflector, a second reflector, a first intensity modulator IM and a first telescope; the Bob end comprises a second laser, a second spatial light modulator SLM2, a second attenuator, a third reflector, a fourth reflector, a second intensity modulator IM and a second telescope; the receiving end Charlie comprises a third telescope composed of a fifth lens and a sixth lens, a fourth telescope composed of a seventh lens and an eighth lens, first to third beam splitters BS, first and second polarization gratings PG, fifth to eighth reflectors, first to fourth mode sorters MS, and first to fourth detectors. The invention further provides an MDI-QKD performance improvement method of the unmanned aerial vehicle platform OAM code based on the grey wolf-differential evolution hybrid algorithm GWO-DE. According to the method, an efficient parameter optimization strategy is provided for an airborne OAM-MDI-QKD system of a fixed link, a data set obtaining scheme for machine learning prediction is provided for meeting the high real-time requirement of a mobile link, and an idea is provided for achieving a safer and more reliable quantum communication network in the future.

Provided is an integrated beam steering device. The steering device includes a substrate, a core layer provided on the substrate, a clad layer on the core layer, a plurality of upper electrodes provided on the clad layer, and a lower electrode provided on a lower surface of the substrate. Here, the substrate includes a source region configured to generate laser beam, a distribution region configured to transmit the laser beam, an amplification region configured to amplify the laser beam, a phase modulation region configured to modulate the phase of the laser beam, and a first intensity modulation region configured to modulate the intensity of the laser beam.

A quantum key distribution system with polarization and phase composite coding includes a transmitting end and a receiving end, wherein the transmitting end includes a laser, an intensity modulator, a polarization coding module, a phase coding module and an electrically adjustable attenuator connected in sequence, and the receiving end includes a phase decoding module, a polarization decoding module and a single-photon detector connected in sequence, and the transmitting end and the receiving end are connected through a single-mode optical fiber. Compared with the prior art, the present invention can improve the efficiency of the protocol by performing phase and polarization composite coding on single-photon bits, and the efficiency can be increased to 4 times of the original protocol by using a partial selection basis; the polarization coding and decoding structure is simple and the performance is stable, which not only reduces the complexity of the system, but also improves the security of the system; the phase coding and decoding module has the characteristic of being polarization-independent, so it will not interact with the polarization coding, and is not affected by channel disturbances, so that the phase coding and decoding process is very stable, and the stability of the overall system is increased.

The invention provides a frequency doubling triangular waveform generation system and method, and relates to the technical field of optical communication, the frequency doubling triangular waveform generation system comprises a first continuous light laser, a second continuous light laser, a first intensity modulator, a wavelength division multiplexer, a second intensity modulator, a radio frequency signal generator, an electric attenuator and a photoelectric detector; the first continuous light laser is connected with the wavelength division multiplexer; the output end of the second continuous light laser is connected with a light input interface of the first intensity modulator, and the output end of the first intensity modulator is connected with the wavelength division multiplexer; the output end of the wavelength division multiplexer is connected with an optical input interface of the second intensity modulator, and the output end of the second intensity modulator is connected with the input end of the photoelectric detector; the output end of the radio frequency signal generator is connected with the radio frequency input interface of the first intensity modulator, and the output end of the radio frequency signal generator is connected with the radio frequency input interface of the second intensity modulator through the electric attenuator. The device is low in cost, simple in structure and easy to operate.

The utility model discloses a nine-path output transimpedance amplification photoelectric detector based on a 3 * 3 PIN matrix photodiode, and the photoelectric detector comprises a light current signal collection module which is used for receiving laser of a specific wave band modulated by an intensity modulator, and comprises the 3 * 3 PIN matrix photodiode; the power input and filter circuit module is used for providing stable power supply voltage for the photoelectric detector; the operational amplifier voltage power supply module is used for ensuring the stability of the output voltage and comprises an operational amplifier positive voltage power supply module and an operational amplifier negative voltage power supply module; the reverse adjustable bias module is used for providing adjustable negative power supply voltage for the matrix photodiode; the transimpedance amplification module is used for effectively reducing noise and errors caused by input current and ensuring rapid rising and falling of an output signal; the voltage amplification module is used for reducing noise interference and improving signal quality and precision; and the signal output module is used for outputting the electric signal.