83results about "Optical measurements" patented technology

An optical component (1) comprises a diffraction grating and a microlens array that are hexagonal and angularly offset from each other by 10° to 50°. Such an optical component is particularly well-suited for use in a wavefront analyzer. The wavefront analyzer can alternatively have two configurations, in which the distance between the optical component and an image sensor is close to f / 2 or 3·f / 2, where f is the focal length of the microlenses (11). Such a wavefront analyzer can be compact, easy to use, and compatible with a wide range of wavelength values ​​for the electromagnetic radiation to be analyzed. (Shorthand figure: Figure 1)

The invention relates to a single-photon spectrometer (10) having at least one dispersion element (40) which has a first optical dispersion, and having a photon detector (30) which is arranged to detect at least one photon (15) which has passed through the dispersion element (40), and having a time-of-flight meter (60) which is designed to automatically measure a propagation time (t) of the at least one photon (15) through the dispersion element (40), wherein the photon detector (30) is designed to automatically determine a wavelength (λ) of the at least one photon (15) from the propagation time (t).

The present disclosure is of an atmospheric characterization system that has a central processing board that has a first and a second communication interface. Further, the atmospheric characterization system further has a first precision temperature sensor that is communicatively coupled to the central processing board via the first communication interface and positioned a distance from a first side of the processing board, wherein the precision temperature measures a first temperature and transfers data indicative of the first temperature to the central processing board. In addition, the atmospheric characterization system has a second precision temperature sensor that is communicatively coupled to the central processing board via the second communication interface and positioned the distance from a second opposing side of the processing board such that the first precision temperature sensor and the second precision temperature sensor are equidistance from the processing board and a distance between the first precision sensor and the second precision sensor is a predetermined distance, r, and the second precision temperature sensor measures a second temperature and transfers data indicative of the second temperature to the central processing board simultaneously with the transferring of the first temperature. Additionally, the atmospheric characterization system has a processor that receives the first temperature and the second temperature and calculates a value indicative of atmospheric turbulence based upon the first temperature and the second temperature, wherein the value indicative of the atmospheric turbulence is used for designing, modifying, calibrating, or correcting an optical system.

A fringe projection-based spatial phase imaging monitoring system using a single optical path includes: a light source; a first beam splitter that transmits a first light and reflect a second light; a tilt mirror that reflects the first light transmitted through the first beam splitter back toward the first beam splitter and varies a phase of the first light; a mirror that reflects the second light reflected by the first beam splitter back toward the first beam splitter; a lens that condenses the first and second lights reflected by the tilt mirror and the mirror; a second beam splitter that transmits the condensed first and second lights toward a sample and reflects light returning from the sample; and an image sensor that captures an image of the sample in which a fringe is formed according to a phase difference between the first and second lights.

According to an aspect of the present inventive concept there is provided a system (100) for measuring frequency of a light signal (112) from a chirped laser source (110), said system (100) comprising: an optical measurement unit (120) configured to receive at least a portion (114) of the light signal (112), and to output, via an optical hybrid coupler (122), at least two angle diversity signals (124) based on a difference between a first and second signal (114a, 114b) formed by splitting the at least portion (114) of the light signal (112), wherein the second signal (114b) is delayed relative to the first signal (114a), and wherein a pair of signals of the at least two angle diversity signals (124) have a fixed phase shift relative to each other; and a control unit (130) configured to: receive the at least two angle diversity signals (124), generate a complex signal, based on the at least two angle diversity signals (124), and determine an instantaneous phase of the complex signal for determining an instantaneous frequency of the light signal (112).

The application belongs to the technical field of wavelength measurement, and is especially a high-resolution speckle wavelength measurement device and method. The device comprises a shell, a first optical fiber incident port and a second optical fiber incident port are arranged on the outer wall of the shell, an optical switch, a light splitting coupler, a calibration light source and a test light path are arranged in the shell, and the test light path is composed of a multimode optical fiber, an optical fiber mode enhancement device and a surface array detector. The application enhances the coupling and phase delay between different modes by applying mechanical disturbance to the scattering medium, increases the number of excited modes, and solves the problems that the resolution of the speckle wavelength meter is limited by the light path length of the transmission medium and the insufficient information density of the speckle per unit area. The method can improve the wavelength resolution, and effectively improve the sampling speed of the speckle wavelength meter by reducing the size of the photosensitive camera target surface.

To provide an optical pulse meter which can reduce a measurement time.SOLUTION: An optical pulse meter 100 comprises: a wavelength variable filter 13 capable of successively changing the transmission wavelength band of first light to be measured that is branched from light to be measured; an optical detector array 14 made by arranging, in array form along a region, a plurality of optical detectors to which first light to be measured having passed through the wavelength variable filter 13 and second light to be measured having been branched from the light to be measured and not having passed through the wavelength variable filter enter, and which output a photocurrent obtained based on exponential strength of light at a plurality of positions in a region where the first light to be measured and the second light to be measured optically overlap; a generation unit 501 for generating a spectrogram on the basis of a photocurrent that corresponds to the transmission wavelength band set by the wavelength variable filter 13 and the position of the region; and an identification unit 502 for identifying the amplitude and phase of the light to be measured, on the basis of the spectrogram generated by the generation unit 501.SELECTED DRAWING: Figure 1

Disclosed is a phase measurement device, comprising: a first wave plate, a first polarization splitting prism, a fourth wave plate, a retroreflector, a third wave plate, a reflector, a second wave plate, a polarizer, a second polarization splitting prism, a third polarization splitting prism, a first photoelectric detector, a second photoelectric detector, and a base, wherein the first to third polarization splitting prisms and the first and second photoelectric detectors are fixed on the base; the first to fourth wave plates are respectively arranged around the periphery of the first polarization splitting prism; the polarizer is arranged on an emitting surface of the third polarization splitting prism; the retroreflector is arranged on an outer side of the fourth wave plate; and the reflector is arranged on an outer side of the third wave plate. An interferometric signal is resolved to obtain a measurement light beam phase.

The application discloses a laser phase noise measurement method based on delay self-heterodyne and digital demodulation, and relates to the technical field of laser measurement, and comprises the following contents: after being adjusted by a variable optical attenuator, to-be-measured laser is divided into a frequency shift arm and a delay arm, the frequency shift arm is frequency-shifted by an acousto-optic modulator, the delay arm is delayed by a delay optical fiber, and original electric beat frequency signals are obtained by a balanced photoelectric detector after the two arms are coupled; homologous and synchronous quadrature demodulation is carried out on the original electric beat frequency signals, envelope credibility judgment and abnormal sample repair are combined, and a continuous differential phase sequence is obtained; actual optical time delay is determined according to the beat frequency spectrum characteristics and the continuous differential phase sequence, and a differential phase power spectral density is formed; then, transmission relationship conversion is carried out according to the actual optical time delay, bounded spectrum compensation is implemented on a zero point neighborhood and a low credibility frequency point, and an intrinsic phase noise power spectral density is obtained. The application can improve the stability, continuity and result credibility of phase noise measurement under the condition of short delay.

The application discloses a spectrum frequency calibration device and method applied to a quantum microwave field strength instrument, wherein a probe light laser emits probe light, atoms in an atomic cell are excited from a ground state to a first excited state; a coupling light laser emits coupling light, atoms in the atomic cell are excited from the first excited state to a Rydberg state; the coupling light is modulated through an electro-optical modulator, a signal source provides a radio frequency driving signal for the electro-optical modulator; an atomic clock provides a frequency reference for the signal source, and a time frequency standard transmission terminal is used for calibrating the atomic clock; the atomic cell stores alkali metal atoms, the probe light and the coupling light form an optical axis passing through a center position of the atomic cell; a photoelectric detector is used for receiving the probe light and converting the probe light into a voltage signal; a data acquisition card records the voltage signal output by the photoelectric detector and forms time sequence voltage data; and a host computer processes the time sequence voltage data to form spectrum data. The application has high measurement precision, adjustable calibration range and simple structure and is easy to implement.

This technology provides a method for calculating wavefront aberration even when the alignment of the target focal points is not parallel to the vertical and horizontal grid lines of the target image. [Solution] A reciprocal lattice image (IR) representing the grid point cloud of the reciprocal lattice (XR) is generated by performing a 2D Fourier transform on the target image (IP). Furthermore, by referring to the grid vector of the reciprocal lattice (XR), a target lattice (XP) is estimated in which the arrangement of its grid point cloud approximates the arrangement of the target focal point cloud (P). Then, each target focal point (p i ) at its target focal point (p i The grid point (p) of the target grid (XP) closest to ) mn Assign lattice coordinates to the target focal point (p i ) and reference focal point (q i Pair it with ).

An optical measurement method includes: preparing an optical system for recording a hologram caused by modulating, with a reference beam, an object beam obtained by illumination of a sample with illumination light, the reference beam being coherent to the illumination light; arranging a calibration unit on an optical path of the illumination light in a state where there is no sample, the calibration unit including an optical system that produces a known optical wave distribution; recording a first hologram caused while the calibration unit is producing an optical wave distribution; and calculating information about an optical wave distribution of the reference beam based on information indicating a position where the calibration unit is arranged, the known optical wave distribution, and the first hologram.

This invention provides a detection method that can appropriately eliminate the influence of factors that hinder the integration of interference waves, thereby achieving highly sensitive detection of interference waves. [Solution] A detection method for detecting interference waves of a dual-comb laser, comprising: acquiring data of the interference wave train generated by the dual-comb laser by sampling; estimating the period of each interference wave included in the acquired interference wave train; correcting the data of each interference wave in the time domain or frequency domain so that the scales of the spectra of each interference wave obtained by Fourier transform match each other based on the estimated period of each interference wave; and integrating and averaging the spectra of each corrected interference wave.

The application discloses a system and method for detecting terahertz waves based on organic polymers, and relates to the field of terahertz detection.The application utilizes the nonlinear interaction between terahertz waves and detection light in an organic polymer film to generate a target signal, and introduces controlled reference light to perform coherent interference, so that the time-domain waveform, amplitude information and phase information of the terahertz electric field are recovered.The application can expand the application range of organic polymer materials in the field of terahertz detection, and provides a new technical approach for constructing a low-cost, high-sensitivity, wide-band and easy-maintenance terahertz coherent detection platform.

An adaptive optical system (1) comprising: - at least one optical device (2) adapted to emit and / or reflect and / or transmit an optical radiation (o_s) having a wavefront; - a first wavefront quality measurement module (3) adapted to acquire a first wavefront error measure of the optical radiation (o_s) to provide a first signal (s1) representative of the first wavefront error measure; - a second wavefront quality measurement module (4) adapted to acquire a second wavefront error measure of the optical radiation (o_s) to provide a second signal (s2) representative of the second wavefront error measure; - a wavefront correction module (5,6) adapted to modify the optical radiation to reduce or eliminate the wavefront error; - a processing module (7) operatively connected to the first wavefront quality measurement module (3) to receive in input the first signal (s1) and operatively connected to the second wavefront quality measurement module (4) to receive in input the second signal (s2) and output, based on the first signal (s1) and the second signal (s2), a control signal (c_s) for controlling said wavefront correction module (5, 6); wherein: - the first wavefront quality measurement module (3) is configured for sampling a plurality of spots of said optical radiation (o_s) according to a sampling resolution that can be controlled by the processing module (7); - the processing module (7) is configured to control the first wavefront quality measurement module (3) to decrease its sampling resolution until the processing module (7) determines that a wavefront of said optical radiation (o_s) can be reconstructed and, after said determination, the processing module (7) is configured to output said control signal (c_s) to perform a first correction through said wavefront correction module (5,6) ; - after performing said first correction, the processing module (7) is configured to execute an iterative routine by acquiring wavefront error measures through said second wavefront quality measurement module (4) and outputting said control signal to perform a second correction through said wavefront correction module (5,6).

The present application relates to the technical field of transient source identification, in particular to a method for quickly identifying optical transient sources based on multi-band light curve, comprising the following steps: acquiring multi-band light variation data phase, labeling missing interval and constructing atlas, identifying trend interference structure and labeling, compensating missing section to generate continuous sequence, extracting derivative difference to construct candidate mutation index, generating response feature vector and matching type label, and outputting transient source candidate type list; in the present application, the missing section is compensated and interpolated by a Gaussian kernel function, a continuous fitting curve sequence is constructed under the coordinated labeling of brightness change direction and derivative slope, the cross-band derivative range aggregation position is extracted by a sliding time window, the light variation mutation characteristics can be captured, after the multi-dimensional response description vector is extracted, the training network is input, a stable response channel can be formed in a multi-type event concurrent scene, the identification accuracy and robustness are effectively improved, and the limitations caused by the dependence of artificial experience on the identification process are avoided.

The invention relates to the technical field of optical engineering, and discloses a handheld laser directional energy system which comprises a Shack-Hartmann wavefront detection system, a visual observation system, an atmospheric turbulence correction system, a laser emission system, a laser ranging system and an anti-shake system. By integrating wavefront detection and adaptive correction, coaxial design, target background difference enhancement through light splitting, MEMS reflector dynamic adjustment, jitter compensation and other technologies, the problems that the imaging quality is interfered by atmospheric turbulence, correction is inaccurate due to system space separation, the contrast ratio of a dark and weak target is poor, aiming is difficult, and jitter miss is caused are solved; the effects of high-resolution imaging, energy concentration, easy target discovery, automatic locking and stable aiming are achieved.

The invention relates to a wavelength detection system that enables the detection of wavelength from light / laser sources using at least two different characteristic photodiodes.

This invention discloses a method for measuring the wavelength of low-coherence lasers using a synthetic Fizeau interferometer cavity. The method involves acquiring the interference fringes and extracting the initial phase of each actual Fizeau interferometer cavity with different free spectral ranges (FSRs) that meet the coherence length requirements of the low-coherence laser to be measured. Based on the FSRs and initial phases of each actual cavity, a synthetic Fizeau interferometer cavity with a FSR smaller than that of the physical cavities is constructed to obtain the synthetic free spectral range and synthetic initial phase. The interference order of the synthetic cavity is then determined by combining the input estimated wavelength or frequency, and wavelength refinement is performed to finally obtain the measurement wavelength. This invention does not limit the specific optical path structure or detector arrangement, and can effectively overcome the limitation of low-coherence laser coherence length on the accuracy of Fizeau wavelength measurement without increasing the optical path difference of the actual Fizeau interferometer cavity or reducing the fringe signal-to-noise ratio.

This invention discloses a phase retrieval method for bright-field microscopy based on uniform light intensity, belonging to the technical field of phase retrieval in optical measurement. The method includes: acquiring focused light intensity images, positive defocus images, and negative defocus images along the optical axis; calculating the axial differential of light intensity using the finite difference method; simplifying the light intensity transmission equation to a Poisson equation and solving the Poisson equation to obtain the initial phase; constructing a positive higher-order error compensation model for the axial differential of light intensity and solving for the phase; and using a gradient acceleration strategy to iteratively calculate the phase to obtain the final phase result. This invention significantly improves the stability and accuracy of phase retrieval. Simultaneously, by combining angular spectrum theory to construct an axial differential higher-order error compensation model and introducing a gradient acceleration strategy, it effectively corrects defocus errors, greatly improves iterative convergence efficiency, and enhances the applicability of the method in practical microscopic imaging scenarios.

This invention relates to the field of dispersive fringe co-phase error inversion technology, and discloses a method and system for dispersive fringe co-phase error inversion based on VU decomposition. The method includes: acquiring the dispersive fringe pattern corresponding to the sub-aperture pair to be co-phased; extracting the effective dispersive fringe signal from the dispersive fringe pattern; performing VU decomposition and iterative update on the effective dispersive fringe signal to obtain a matrix V representing the orthogonal characteristic basis of the fringe spatial domain; based on the matrix V representing the orthogonal characteristic basis of the fringe spatial domain, obtaining the wrapped phase of the co-phase error modulation through an arctangent function; unwrapping the wrapped phase through a phase unwrapping function to obtain the unwrapped phase; and linearly fitting the unwrapped phase and the wavenumber coordinates of the effective dispersive fringe signal along the dispersion direction to obtain the co-phase error. This invention can achieve co-phase error inversion without preprocessing or auxiliary information.

An apparatus and method determine a fluorescence lifetime of a sample with a Mach-Zehnder interferometer. A beam splitter interferes a fluorescence signal traveling in a first arm with a frequency-matched reference pulse in a second arm, yielding two combined outputs. A first single-photon detector converts the first output into a signal proportional to its photon count, and a second detector produces an analogous signal for the second output. By correlating the detectors' signals while systematically varying the relative optical path delay between the interferometer arms, the system extracts the fluorescence lifetime of the sample.

This invention relates to the field of radio frequency signal measurement technology, and proposes a microwave photonic system and method for nanosecond-level measurement of frequency and angle of arrival. The system includes: an optical frequency comb generation module, in which a narrow-linewidth laser generated by a tunable laser is amplified by an erbium-doped fiber amplifier and then excited by the Kerr nonlinear effect to generate a coherent optical frequency comb; an antenna receiving module, which receives a first radio frequency signal and a second radio frequency signal; an electro-optic modulation module, in which the first radio frequency signal and the second radio frequency signal are respectively input to a first sub-modulator and a second sub-modulator, and a third sub-modulator is used to combine the first and second modulated lights and introduce a preset phase difference to obtain a target optical pulse signal; and a frequency-time mapping and detection module, in which the target optical pulse signal is frequency-time mapped via a dispersive fiber, a photodetector converts the mapped optical signal into an electrical pulse train, and an oscilloscope is used to observe the time interval between adjacent peaks and the pulse amplitude information of the electrical pulse train to obtain the characteristic parameters of the radio frequency signal.

This invention relates to a testing device and method for the frequency variation of wavefronts in atmospheric turbulence and aerodynamic effects, belonging to the field of photoelectric system tracking and control. The device includes: a photodetector, a spatial intensity distribution modulation plate, a lens, and a beacon light source. The beacon light source modulates its wavefront information through the lens and the spatial intensity distribution modulation plate, converting it into intensity information. The photodetector collects the intensity information. A thin-film panel is fabricated on the lens. The beneficial effects of this invention are: it converts the spatial distribution characteristics of the wavefront into intensity information and achieves the acquisition of the temporal characteristics of the wavefront information through a high-speed photodetector, enabling a measurement bandwidth at the MHz level, thus providing support for the study of strong turbulence and aerodynamic effects.

A dispersion measurement device includes a pulse forming unit, an optical detection unit, and an arithmetic operation unit. The pulse forming unit includes an SLM that presents a phase pattern giving a predetermined phase shift for each of wavelength to the first optical pulse, and forms an optical pulse train from the first optical pulse, the optical pulse train including a plurality of second optical pulses having a time difference from each other and having center wavelengths different from each other. The optical detection unit detects a temporal waveform of the optical pulse train. The arithmetic operation unit is electrically connected to the optical detection unit. An optical component is arranged on an optical path between the pulse forming unit and the optical detection unit. The arithmetic operation unit estimates a wavelength dispersion amount of the optical component based on a feature amount of the temporal waveform. The phase pattern of the SLM includes a pattern for giving a group delay dispersion having a sign opposite to the group delay dispersion of the optical component to the first optical pulse.

The application discloses a kind of super large dynamic range Shack-Hartmann wavefront reconstruction methods, it is related to wavefront detection technical field, including: obtaining reference spot array image, and for each reference spot allocation ID;Obtain the spot array image sequence formed by wavefront to be measured;Perform global spot detection, obtain the centroid position set of all observation spots in frame;The observation spot of current frame is globally data associated with the historical spot trajectory established;For the observation spot matched successfully, with its centroid position as measurement value, update the state tracker of corresponding ID;For each spot successfully maintaining identity ID, calculate the displacement vector between its current centroid position and corresponding initial reference centroid position;Based on displacement vector, reconstruct the wavefront phase to be measured.The method can expand the determinant of dynamic range from sub-aperture geometric parameters to detector physical field of view while maintaining spatial resolution and sensitivity by algorithm upgrade only.