64 results about "Optical phase modulator" patented technology

The invention discloses an ODAC implementation system and method based on a five-segment thermo-optical phase modulator, and relates to the technical field of optical communication, and the method comprises the following steps: obtaining single-mode laser input, dividing the single-mode laser input into two paths through a multi-mode interference device beam splitter, and transmitting the single-mode laser input into an upper arm and a lower arm of a Mach-Zehnder modulator; the current is adjusted through the thermo-optic phase modulator to control the temperature, the refractive index is changed to introduce phase delay, and the phase difference of two arms of the Mach-Zehnder modulator is calibrated; on the basis of a five-segment thermo-optical modulator, hierarchical amplitude modulation is carried out on beam splitting light according to digital input, a phase space is constructed by utilizing weight combination, and a linear optimal discrete state is screened; the modulated light is combined by a multi-mode interference device beam combiner, and digital-analog mapping output of light intensity is carried out; a detector installed at an output port of the five-segment thermo-optical phase modulator is used for monitoring output optical power in real time, the output optical power is fed back to a control circuit to calculate errors, thermo-optical modulation current is dynamically adjusted to compensate offset point drift, and optical digital analog conversion is achieved.

To provide mechanisms for providing a source for circular-ranging OCT at moderate speeds.SOLUTION: A source for providing electromagnetic radiation within a particular spectral range includes: a ring-shaped optical resonator for circulating a plurality of wavelength bands including a first optical phase modulator, a first chromatic dispersion device, a second optical phase modulator, a multi-line spectral domain filter, a second chromatic dispersion device, and an optical amplifier; and a controller coupled to the first optical phase modulator and the second optical phase modulator, the controller being configured to drive the first optical phase modulator with a first waveform and the second optical phase modulator with a second waveform.SELECTED DRAWING: Figure 2

An imaging optical system according to the present disclosure includes: an aperture stop; an image-forming optical system that causes an image to be formed toward an imaging plane of an image sensor; and an optical phase modulator that includes a substance having a birefringence index, and gives two pupil functions to the image-forming optical system. The following conditional expressions are satisfied:1≤(2×L×tan(w)+D) / D<1.4  (1)λ / 4*0.75<Re<λ / 4*1.1  (2), whereL: a distance between the aperture stop and the optical phase modulator; D: an aperture diameter (diameter) of the aperture stop; w: a maximum angle of incidence of a principal light ray that enters the aperture stop; λ: a wavelength of light; and Re: phase retardation caused by birefringence of the optical phase modulator.

An integrated photonics millimeter wave (MMW) radar communication system based on analog phase modulation scheme includes an integrated photonics MMW radar communication signal transmitter, a radar receiver, and a communication receiver. The transmitter includes a radar communication signal analog phase modulation module, an optical frequency comb (OFC) module, an electro-optic modulator (EOM), an optical shaping filter, an optical power divider, a photoelectric detector, an electric power amplifier, and a transmitting antenna that are cascaded sequentially. The radar receiver includes a radar receiving antenna, an electric low-noise amplifier (LNA), an optical phase modulator, an optical bandpass filter (BPF), a low-speed photoelectric detector, an electric low-pass filter, and a low-speed oscilloscope that are cascaded sequentially. In the communication receiver, a communication receiving antenna is sequentially cascaded with an electric LNA, a frequency mixer, and an oscilloscope, and a voltage-controlled oscillator is cascaded with a frequency multiplier and then connected to the frequency mixer.

The invention discloses a lithium niobate electro-optical polarization modulator based on an adiabatic coupling structure and a modulation method thereof. The modulator comprises a first adiabatic coupling polarization beam splitting rotator, an electro-optical phase modulator and a second adiabatic coupling polarization beam splitting rotator, wherein each adiabatic coupling polarization beam splitting rotator comprises an input waveguide, an adiabatic coupler and a separation waveguide. According to the modulation method, transmission is carried out through a straight-through end in a first adiabatic coupling type polarization beam splitting rotator, and TE0 is kept unchanged; when the input light is TM0, the input light is converted into TE0 through the first adiabatic coupling type polarization beam splitting rotator and is transmitted through the cross end. And after phase modulation is carried out by the electro-optic phase modulator and beam combination is carried out by the second adiabatic coupling type polarization beam splitting rotator, output light is remapped into TE0 and TM0, and the polarization state is determined by the relative phase difference, so that dynamic regulation and control of the polarization state are realized.

A photonic integrated circuit (PIC) is disclosed herein. The PIC can include a substrate, a main optical waveguide supported by the substrate. The main optical waveguide can be in communication with an electromagnetic radiation source, and configured to receive electromagnetic radiation from the electromagnetic radiation source. A first branch optical waveguide can be optically coupled to the main optical waveguide at a first location. An optical phased array (OPA) can include plurality of array elements, each having an optical antenna and an optical phase modulator. At least some array elements within a first subset of the plurality of array elements can be optically coupled to the first branch optical waveguide wherein locations of at least some of the plurality of array elements are aperiodic in one or more directions on the substrate.

A large-scale distributed photoelectric intelligent computing system, including: a diffractive compression encoder, configured to collect two-dimensional light field information through a grating array, convert the two-dimensional light field information into one-dimensional information through waveguide transmission and transmit the one-dimensional information to a first diffractive region, and perform computing using a diffractive coding weight to output a one-dimensional vector through an output end of the first diffractive region; a reconfigurable interference feature embedder consisting of an interferometer array composed of a plurality of thermo-optical phase modulators, in which the interferometer array is configured to perform a multiplication operation on the one-dimensional vector, to output a computed result in a one-dimensional vector form; and a diffractive decoder, configured for diffractive decoding the computed result in the one-dimensional vector form through a second diffractive region, to compute and output final light field information through a diffractive decoding weight.

A spectral linewidth adjusting method includes: adjusting a timing of a first trigger signal for amplifying and converting a portion of a first pulse laser beam to a second pulse laser beam and / or a timing of a second trigger signal for amplifying and converting a portion of second continuous light to a third pulse laser beam and adjusting a spectrum of a fourth pulse laser beam obtained by performing sum-frequency mixing of the second and third pulse laser beams to a first spectrum in a non-Gaussian shape; and modulating a wavelength of the second continuous light within time corresponding to one pulse of the third pulse laser beam and adjusting the spectrum of the fourth pulse laser beam to a second spectrum having a spectral linewidth wider than the first spectrum through generation of a modulation signal for supplying the modulation signal to an optical phase modulator.

The invention relates to an electro-optical crystal half-wave voltage temperature correlation detection method and system. The system comprises a light source, a polarizer, an optical phase modulator, an isolation optical fiber, an electro-optical crystal to be detected and a polarization analyzer which are sequentially arranged along a light path. The included angle between the light transmitting direction of the polarizer and the fast axis direction of the optical phase modulator is 45 degrees; the included angle between the light transmitting direction of the polarization analyzer and the fast axis direction of the electro-optical crystal to be detected is 45 degrees; applying voltage to the optical phase modulator, wherein the voltage amplitude is 1 / 4 wavelength voltage of the optical phase modulator; constructing a light path inherent function; the environment temperature of the electro-optical crystal to be detected is changed, the intensity of output light at different temperatures is detected, the nearly 1 waveform variation is calculated according to the light intensity, and the correlation between the electro-optical coefficient of the electro-optical crystal to be detected and the temperature is judged according to the nearly 1 waveform variation.

An optical phase modulator includes a first layer made of dielectric material with a waveguide and a heater extending therein; at least one upper trench arranged above the heater and side trenches arranged on either side of the waveguide and the heater, and a second layer made of dielectric material extending over the first layer made of dielectric material and covering each first, second and third trench.

The invention belongs to the technical field of light beam synthesis, and particularly discloses a coherent synthesis light source regulation and control device and method for pulse output. Comprising a plurality of single-frequency lasers used for outputting single-frequency laser; the optical phase modulators are arranged in one-to-one correspondence with the single-frequency lasers and are used for performing phase adjustment on the single-frequency lasers; a plurality of polarizers which are arranged in one-to-one correspondence with the optical phase modulators and are used for carrying out polarization processing on the single-frequency laser after phase adjustment; the gathering device is used for carrying out focusing processing on the plurality of single-frequency lasers processed by the polaroid; the synthesis grating is used for coherently synthesizing the plurality of focused single-frequency lasers into a beam of pulse laser and outputting the pulse laser; the angles of the multiple single-frequency laser beams incident on the synthesis grating meet the grating diffraction synthesis relation. According to the invention, the diffractive optical element is adopted to coherently combine a plurality of continuously output single-frequency laser beams, so that high-average-power and high-peak pulse laser source output is realized, and the laser pulse width is adjustable.

The application discloses a Stokes parameter encoder, which comprises a fiber optical circulator and an optical path round trip path; a polarization maintaining fiber Faraday rotator is arranged on the optical path round trip path to rotate the polarization of light by 45 degrees; the fiber optical circulator is a polarization maintaining fiber optical circulator; the fiber optical polarization beam splitter is a polarization maintaining fiber optical polarization beam splitter; the delay fiber is a polarization maintaining delay fiber; and the fiber optical phase modulator is a polarization maintaining fiber optical phase modulator. The application further discloses a parameter encoding method of the encoder. The above technical scheme can perfectly offset the rotation angle deviation problem caused by the device, can guarantee the stability of the rotation angle regardless of the angle deviation of the device, is easy to realize the driving circuit, is easy to integrate and small in size due to the pure fiber structure, and can realize the continuous variable quantum key distribution of the complete GG02 protocol based on the Stokes encoder.

This application relates to a Rayleigh scattering noise suppression method and system for a distributed acoustic wave detection system. The method includes: performing optical phase sinusoidal modulation on a high-coherence continuous laser output from a narrow-linewidth laser in an FBG-based distributed acoustic detection system according to a set modulation scheme using an optical phase modulator; the set modulation scheme is Csin(2πf m t), C is the phase modulation amplitude, f m The phase modulation frequency and satisfying f m τ = k, where τ is the time difference between two adjacent reflected light pulses being detected, t is time, and k is an integer. A highly coherent continuous laser beam with sinusoidal phase modulation is passed through an unbalanced interferometer to generate dual light pulses. These dual light pulses are then injected into an FBG array for distributed acoustic wave detection. This achieves low-noise distributed acoustic wave detection and effectively improves the detection performance of FBG-based distributed acoustic wave detection.

The present application discloses a distributed optical phase modulator, comprising: a substrate, and an optical waveguide arranged on the substrate; a driving electrode, arranged on the substrate, including a plurality of sub-driving electrodes arranged at intervals, and at least one shielding electrode, at least partially spaced from the sub-driving electrode; the optical waveguide sequentially passes through the sub-driving electrodes and the shielding electrodes. The length of the driving electrode of each part is much smaller than the total length of the equivalent traditional modulator, and the driving signal voltage of each part is also much smaller than the driving signal voltage of the equivalent traditional modulator. In the driving electrode of each part, the propagation of the optical signal can achieve approximately synchronous propagation or even synchronous propagation with the electrical signal. The walk-off phenomenon between the photoelectric signals is minimized, and the upper limit of the modulation bandwidth is increased. Shielding electrodes are respectively arranged between the sub-driving electrodes to shield the crosstalk between the sub-driving electrodes, which can greatly reduce the crosstalk between the sub-driving electrodes.

A light source for a frequency-modulated continuous-wave (FMCW) LiDAR device is formed by a photonic integrated circuit and comprises a substrate and a multilayer structure. Formed in the multilayer structure is a semiconductor laser that is received in a recess etched into the multilayer structure. An optical path between the semiconductor laser and a reflector forms an external cavity for the semiconductor laser. The external cavity includes a variable attenuator causing an attenuation of light guided in the cavity optical waveguide. The external cavity may also or alternatively include an optical phase modulator.

A system includes at least one laser configured to produce laser light and an optical element configured to produce shaped light responsive to receiving the laser light. The system also includes an optical phase modulator (OPM) optically coupled to the optical element, the OPM configured to modulate the shaped light to produce modulated light, where the optical element is configured to reduce a point spread function of the modulated light in a far field.

The present disclosure provides an optical waveguide modulation device and an optical phase modulator. The optical waveguide modulation device comprises a substrate, an isolation layer arranged on the substrate, a ridge waveguide structure arranged on a side of the isolation layer away from the substrate, comprising a first slab layer arranged on a side of the isolation layer away from the substrate, and a ridge protrusion layer arranged on a side of the first slab layer away from the isolation layer, and a first metal layer arranged on a side of the isolation layer away from the substrate and located on both sides of the ridge waveguide structure, wherein the first metal layer extends to the side of the first slab layer away from the isolation layer towards the ridge waveguide structure to cover the two side edges of the first slab layer. The technical scheme of the embodiment of the present disclosure can reduce the electromagnetic field leakage on both sides of the first slab layer of the ridge waveguide structure, so that the electric field entering the ridge structure is more concentrated, thereby improving the modulation efficiency of the optical waveguide modulation device.

This invention discloses an ultra-low residual amplitude modulation waveguide-optical phase modulator, comprising a first electrode layer and a second electrode layer parallel to each other. An α-phase waveguide channel and a substrate layer are disposed between the first and second electrode layers. The optical axes of the α-phase waveguide channel and the substrate layer are both perpendicular to the plane of the first electrode layer. The difference between the thermo-optical coefficient of the α-phase waveguide channel and the thermo-optical coefficient of the substrate layer is less than a preset thermo-optical coefficient difference threshold. Part of the side of the α-phase waveguide channel is covered by the substrate layer. The electric field between the first and second electrode layers uniformly covers the entire α-phase waveguide channel and the substrate layer. The two ends of the α-phase waveguide channel serve as the input and output ends of the light beam, respectively. This invention, by changing the electric field application method and thermo-optical coefficient matching, fundamentally maintains the consistency of the interference phase, thereby significantly reducing the sensitivity of RAM signals to voltage and ambient temperature fluctuations.

The present invention provides a self-calibration method for a fiber optic gyroscope and a fiber optic gyroscope. The self-calibration method includes applying a calibration signal to an optical phase modulator; performing time-series demodulation on a signal collected by a light detector to obtain gyro outputs in the first and second half-cycles of a calibration state; calculating a calibrated scale factor; calculating a zero-position error caused by scale factor drift and a primary calibration gyro output for scale factor calibration; calculating a secondary calibration gyro output for zero-position calibration based on the time-series demodulation result; and calculating the gyro output after the secondary calibration. A calibration state is introduced into the fiber optic gyroscope signal processing. In the calibration state, a periodic calibration signal is output and loaded onto a phase modulator to simulate the positive and negative rotational speeds of the gyroscope. The gyro zero bias and scale factor are adjusted through calibration calculations.

The present disclosure relates to the field of electro-optical devices. Specifically, the present disclosure provides a monolithically integrated electro-optical phase modulator fabricated using a III-V semiconductor process on silicon. The phase modulator includes a silicon-based n-type substrate base layer and a III-V n-type ridge waveguide for propagating light, wherein the ridge waveguide protrudes from and extends along the n-type substrate base layer. In addition, the phase modulator includes one or more insulating layers provided on the ridge waveguide, and a silicon-based p-type cap layer provided on the one or more insulating layers, at least above the ridge waveguide, wherein the one or more insulating layers have a total thickness of 1-100 nm.

A wavelength-mode hybrid multiplexer based on a cascaded multimode interferometer structure belongs to the field of silica integrated optics technology. From bottom to top, it consists of a silicon substrate, a silica lower cladding, a germanium-doped silica core layer, and a silica upper cladding. The germanium-doped silica core layer and the upper cladding are located together on the lower cladding, and the core layer is coated in the upper cladding. The germanium-doped silica core layer is composed of a 1×2 Y-branch waveguide, an optical phase modulator, a 2×2 multimode interferometer, a first 1×2 multimode interferometer, a second 1×2 multimode interferometer, a first 1×1 multimode interferometer, and a second 1×1 multimode interferometer. This wavelength-mode hybrid multiplexer adopts a passive structure. Through the optical phase modulator on the modulation arm waveguide and the self-imaging principle of the multimode interferometer structure, it can multiplex and demultiplex the four input signals: TE0 and TE1 at a wavelength of 1550nm and TE0 and TE1 at a wavelength of 1620nm.

Quantum key distribution, QKD, transmitter apparatus including a beam splitter configured to receive an initial pulse train of optical pulse pairs, a first photodetector, an optical storage line, a phase modulator, a polarisation rotation mirror, a second photodetector and processing circuitry configured to:determine first arrival times, tlin, of optical pulses detected at the first photodetector;determine second arrival times, tlout, of optical pulses detected at the second photodetector;determine a time delay, t, based on a time difference, Dt, between a second arrival time and a respective first arrival time; andgenerate an electric modulation signal configured to cause the optical phase modulator to phase modulate one of the optical pulses of optical pulse pairs of the second pulse train for modulation periods based on respective first arrival times plus the time delay.

The invention relates to a spatial domain measurement distributed optical fiber acoustic wave sensing system and a measurement method thereof, the system comprises a light source, and an optical phase modulator, an optical amplifier, an optical circulator and an optical fiber for distributed sensing which are sequentially arranged on a light path of incident light of the light source, and the optical circulator is also located on a light path of light returned from the full length range of the optical fiber. The optical circulator is sequentially connected with a photoelectric detector, a data acquisition card and a computer on the light path of the return light; the optical phase modulator comprises a first radio frequency source, a second radio frequency source, a first electronic switch, a second electronic switch, a frequency mixer and an acousto-optic modulator. According to the invention, a double heterodyne pulse modulation injection technology is combined with a spatial domain phase demodulation method, so that continuous distributed synchronous measurement of a vibration field / sound wave field in a full length range of the optical fiber is realized, and the sensing precision and the spatial resolution are remarkably improved; the core requirements of geophysical exploration, energy industry monitoring, large-scale structure health monitoring and other scenes on spatial domain signal analysis can be met.

The invention provides a spectrum testing method for electro-optical modulation signals. The device is composed of a laser, a microwave signal source, a to-be-measured electro-optical modulation signal generation module, an optical frequency shifter, an electro-optical phase modulator, a photoelectric detector and a spectrum analysis module, optical signals output by the laser are divided into two paths, the upper path is in optical connection with the to-be-measured electro-optical modulation signal generation module, and the lower path is in optical connection with the to-be-measured electro-optical modulation signal generation module. The lower path is sequentially and optically connected with the optical frequency shifter and the electro-optic phase modulator and is optically connected with the photoelectric detector after being combined, the microwave signal source is electrically connected with the radio frequency end of the electro-optic phase modulator, and the output end of the photoelectric detector is electrically connected with the spectrum analysis module. Heterodyne mixing signals f1-pf2 (p is a positive integer) of an electro-optical modulation spectrum signal f1 to be detected and an electro-optical phase modulation signal f2 are detected, mixing signal power ratios when output signal voltages of a microwave signal source are V2 and kV2 respectively are analyzed, the p value and the frequency f1 are determined by utilizing the Bessel function relation, meanwhile, the frequency response of a photoelectric detector is calibrated, and the frequency response of the photoelectric detector is calibrated. The relative amplitude of each order of light modulation sideband of the electro-optical modulation spectrum to be tested is obtained, and spectrum testing of the electro-optical modulation signal to be tested is achieved.

This invention provides a method for narrowing the spectral linewidth of a laser beam to a level where chromatic aberration is negligible. [Solution] The adjustment method includes: a first step of adjusting at least one of the timing of a first trigger signal that amplifies a portion of the first pulsed laser light and converts it into a second pulsed laser light, and the timing of a second trigger signal that amplifies a portion of the second continuous light and converts it into a third pulsed laser light, thereby adjusting the spectrum of the fourth pulsed laser light, which is obtained by sum-frequency mixing of the second pulsed laser light and the third pulsed laser light, to a first spectrum with a non-Gaussian shape; and a second step of causing a modulation signal generator to generate a modulation signal of the same pattern synchronized with the emission trigger signal, and providing the modulation signal of the same pattern to an optical phase modulator, thereby modulating the wavelength of the second continuous light within a time corresponding to one pulse of the third pulsed laser light, thereby adjusting the spectrum of the fourth pulsed laser light to a wider spectral linewidth.

This disclosure provides a thermo-optical phase modulation device and an optical phase modulator. The thermo-optical phase modulation device includes: a substrate; an isolation layer disposed on the substrate; an integrated waveguide structure disposed on the side of the isolation layer away from the substrate, including a first waveguide and a second waveguide, the first waveguide being disposed on the side of the isolation layer away from the substrate, the second waveguide being disposed on the side of the first waveguide away from the substrate, and the projection of the second waveguide along a first direction Z being located above the first waveguide; and a cover layer disposed on the side of the first waveguide away from the isolation layer and covering the integrated waveguide structure. The first waveguide has a first refractive index, the second waveguide has a second refractive index, and the first refractive index is different from the second refractive index. The technical solution of the embodiments of this disclosure can achieve optimized configuration of the function of the thermo-optical phase modulation device, especially improving the thermal modulation efficiency of the thermo-optical phase modulation device.

The present application provides an automated testing device and method for the high-frequency characteristics of a high-speed electro-optical phase modulator, which belongs to the field of high-speed electro-optical phase modulator testing devices. The device controls a radio frequency signal generating module through a control processing module to send radio frequency signals of different frequencies and peak-to-peak values ​​to the electro-optical phase modulator to be tested. The control processing module obtains a power value measured by a power meter, and calculates the half-wave voltage of the electro-optical phase modulator to be tested through the power value, thereby achieving the effect of automated detection of the high-frequency characteristics of the electro-optical phase modulator to be tested. The automated detection device disclosed in the present application is not only simple and reliable in structure, but also easy to operate. In addition, the automated detection device can also perform real-time measurement and stability monitoring of the half-wave voltage of the high-speed electro-optical phase modulator, so as to achieve the technical effect of further expanding the use scenarios of the automated testing device.

A semiconductor optical phase modulator includes an optical phase modulation element, a first semiconductor optical amplifier to amplify light input to the optical phase modulation element, and a second semiconductor optical amplifier to amplify modulated signal light output from the optical phase modulation element. A light input end of the semiconductor optical phase modulator is a light input end face of the first semiconductor optical amplifier. A light output end of the semiconductor optical phase modulator is a light output end face of the second semiconductor optical amplifier.

The invention belongs to the technical field of underwater optical communication, and particularly discloses a high-speed modulation system for underwater high-power laser communication, which comprises a laser, a Mach-Zehnder modulator, a modulation driving module and a laser transmitter, the laser is used for outputting narrow-linewidth linearly polarized laser to the Mach-Zehnder modulator, and the linearly polarized laser has high coherence and stable polarization direction; the Mach-Zehnder modulator adopts a two-arm structure and can divide a light beam into two paths; the two-arm structure is internally provided with an electro-optic phase modulator, and the electro-optic phase modulator carries out phase control by introducing an optical path difference into a voltage signal provided by a modulation driving module; and the laser modulated by the Mach-Zehnder modulator is emitted by the laser emitter and is used for underwater laser communication. According to the invention, the structural limitation that a traditional underwater optical communication system cannot consider the laser power, the modulation rate and the device adaptability at the same time is broken through, and a new technical solution is provided for constructing a long-distance, high-rate and high-reliability underwater laser communication system.

A laser device includes a semiconductor laser outputting continuous light, a first amplifier amplifying the continuous light and converting the continuous light to pulse light in synchronization with a light emission trigger signal received from an external apparatus, an optical phase modulator arranged on an optical path of the continuous light between the semiconductor laser and the first amplifier, a modulation signal generator outputting a modulation signal to be provided to the optical phase modulator, and a processor controlling the modulation signal generator. The processor causes the modulation signal generator to generate the modulation signal having an identical pattern in synchronization with the light emission trigger signal and provide the modulation signal to the optical phase modulator so as to modulate a wavelength of the continuous light within a time period corresponding to one pulse of the pulse light and adjust a spectral line width of the pulse light.