The present disclosure provides a radio frequency tagging optical spectrometer, comprising: a dynamic dispersion device, the dynamic dispersion device receiving a beam comprising more than two wavelength components and being driven by driving radio frequency signals, and the dynamic dispersion device encoding the intensity of each wavelength component into the amplitude of a different beat radio frequency signal based on different driving radio frequency signals, wherein the beat frequency of the different beat radio frequency signal is equal to the frequency of the corresponding driving radio frequency signal; a single-channel photodetector for detecting the sum of beat radio frequency signals formed by adding all the beat radio frequency signals; and a processing unit for performing Fourier transform on the sum of the beat radio frequency signals to obtain a spectrum or an associated radio frequency spectrum by which the optical spectrum is obtained.

A system is described that combines spectropolarimetry with scatterometry. The system uses an annular mirror and liquid crystal devices to control the angle of the incident light cone, the polarization and wavelength, an imaging setup and one or more video cameras so that spectroseopic-polarimetric-scatterometric images can be grabbed rapidly. The system is also designed to incorporate additional imaging modes such as interference, phase contrast, fluorescence and Raman spectropolarimetric imaging.

Provided are a device (4) and a method for online measuring a spectrum for a laser device. The device (4) for online measuring a spectrum for a laser device includes: a first optical path assembly (G1) and a second optical path assembly (G2), and the second optical path assembly (G2) and the first optical path assembly (G1) constitute a measurement optical path. The second optical path assembly (G2) includes: an FP etalon (15) and a grating (18). The homogenized laser beam passes through the FP etalon (15) to generate an interference fringe. The grating (18) is arranged after the FP etalon (15), or is arranged before the FP etalon (15) in the measurement optical path, and is configured to disperse the laser beam passing through the FP etalon (15). A high precision measurement in a wide range for a central wavelength of a laser beam and an accurate measurement for spectral parameters of a corresponding FWHM and E95 are achieved through an arrangement of the FP etalon and the grating “in series” in the measurement optical path. There is no moving element in the measurement optical path, the structure is simple and compact, the measurement precision is high, and the stability is high. The corresponding measurement algorithm is simple and efficient, and has an extremely high scientific research or commercial application value.

Disclosed is an optical sensor, including an external cavity laser configured to output sensing light and reference light; and a photodetector configured to detect a beating signal by an interference of the sensing light and the reference light output from the external cavity laser, in which the external cavity laser includes a reflecting filter including a sensing grating, to which a sensing object is attachable, and a reference grating, which is disposed on the same plane as that of the sensing grating, and outputs sensing light reflected from the sensing grating and reference light reflected from the reference grating. Accordingly, the optical sensor does not require a high-resolution spectroscope and has improved resolution and sensitivity.

Apparatus and method for detecting light, the apparatus comprising: means for splitting an input beam of light, which is obtained from an optical coherence tomography arrangement into at least a first and a second beam of light; means for modulating the first beam of light to provide a first modulated beam of light and means for modulating the second beam of light to provide a second modulated beam of light; means for dispersing the first modulated beam of light to provide a first dispersed beam of light and means for dispersing the second modulated beam of light to provide a second dispersed beam of light; means for detecting the first dispersed beam of light and means for detecting the second dispersed beam of light, the means for detecting being configured to convert the detected beams of light into electrical output signals.

In some examples, an apparatus may include a laser, a source fiber that delivers the laser radiation to an object, and a detector fiber that receives scattered laser radiation and illuminates a detector array with the scattered laser radiation to form speckles on the detector array. In some examples, the object may be directed illuminated by a laser. The detector array may include a plurality of detectors, and may be positioned to receive the scattered laser radiation from the end of the detector fiber. The distance between the detector array and the end of the detector fiber may be adjustable. A controller may be configured to receive detector data from the detector array, determine a time-dependent intensity autocorrelation function for each detector of a plurality of detectors, and determine an ensemble average autocorrelation function. The apparatus may provide information relating to dynamic processes within the object. Various other methods, systems, and computer-readable media are also disclosed.

The present application provides a spectral phase interference device and system for addressing the problem of low stability and compactness with prior art spectral phase interference devices. In the device or system provided in the present application, the optical element for generating the pulse pair to be measured consists of only a birefringent crystal and the adjustment of two-step phase shift is also completed by only a broadband quarter-wave plate. Therefore, wide application of optical elements such as pulse stretchers, retarders, optical splitters and mirrors as in prior art devices is avoided, thereby significantly simplifying the overall device's structure and resulting in enhanced stability and compactness at the same time.

An optical device disperses a wavelength of light and includes: a dispersion element configured to transmit incident light and disperse the incident light so that an optical path is different for each wavelength and to generate first dispersed light; and a reflection unit including four reflection surfaces sequentially reflecting the first dispersed light. The first dispersed light sequentially reflected from the four reflection surfaces is incident on the dispersion element and is transmitted through the dispersion element.

A thickness measuring apparatus for measuring a thickness of a wafer includes a light source emitting light having a transmission wavelength region to the wafer, a focusing unit applying the light emitted from the light source to the wafer held on a chuck table, an optical branching section branching the light reflected on the wafer held on the chuck table, a diffraction grating diffracting the reflected light branched by the optical branching section to obtain diffracted light of different wavelengths, an image sensor detecting an intensity of the diffracted light obtained by the diffraction grating to produce a spectral interference waveform, and a computing unit computing the spectral interference waveform produced by the image sensor to output thickness information.

A multi-modal functional OCT imaging methodology and system are provided that enable concurrent intrinsic optical signal (IOS) imaging of stimulus-evoked neural activity and hemodynamic responses at capillary resolution. An OCT angiography (OCTA)-guided IOS analysis is used to separate neural-IOS and hemodynamic-IOS changes in the same retinal image sequence. The OCTA-guided IOS data processing used for this purpose differentiates two functional images, namely, a neural-IOS map and a hemodynamic-IOS map, from the same image dataset.