Aspects relate to a handheld spectroscopy scanner including an optical window configured to receive a sample and a housing having the optical window thereon. The housing further includes therein a light source and a spectral sensor including a light modulator and a detector. The scanner housing further includes a processor configured to receive a spectrum of the sample from the spectral sensor based on interaction of light produced by the light source with the sample on the optical window. The processor is further configured to produce spectral data based on the sample spectrum for input to an artificial intelligence engine to produce a result based on the spectral data. In addition, the scanner housing may include a flange holding the light source and a heat sink configured to dissipate the internal heat generated. The housing further includes a cavity forming a handle for easy operation of the handheld spectroscopy scanner.

A system for infrared analysis over a wide field area of a sample is disclosed herein that relies on interference of non-diffractively separated beams of light containing image data corresponding to the sample, as well as a photothermal effect on the sample.

A spectrometry device wherein light rays emitted from an object face measurement point combine into one parallel light beam by an objective lens, this is divided into a first and second light beam by a phase shifter, and the first and second light beam emit toward a light-receiving face of a photodetector while providing an optical path length difference. A light-shielding plate is arranged on a face optically conjugate the object face respective to the objective lens, and only light passed through translucent portions of the light-shielding plate is directed to the objective lens. A lateral length of each light-shielding plate translucent portion and the interval between two adjacent translucent portions are based on the objective lens focal length, the distance from the phase shifter to the photodetector light-receiving face, a photodetector pixel pitch, a pixel length, and a predetermined wavelength range of the light emitted from the measurement point.

A frequency-measurement method uses a dual frequency-comb spectrometer as an optical wavemeter to measure the frequency of a reference laser that is used to frequency-stabilize the spectrometer. The method includes measuring a walking rate of center bursts in a sequence of interferograms recorded by the spectrometer, determining a number of teeth in each of a plurality of Nyquist windows formed by the dual frequency-comb spectrometer, and determining a Nyquist number of the one Nyquist window covering the laser frequency. The reference laser frequency can then be determined from the number of teeth in each Nyquist window, the Nyquist number, and the comb spacing of either one of the two frequency combs of the dual frequency-comb spectrometer. The reference laser frequency does not need to be measured with a separate wavemeter, or calibrated with respect to a known atomic or molecular transition.

Raman spectroscopy data is collected using a Spatial Heterodyne Spectrometer and processed in order to reduce signal noise. The processing of the Raman spectroscopy data includes segmenting generating an interferogram from the Raman spectroscopy data, segmenting the interferogram, determining an estimate of power spectrum density, and averaging the estimates of power spectrum density for each segment to provide an output spectrum. The output spectrum has greatly reduced variance of the individual power measurements, and allows the length of segments to be optimized to balance noise reduction operations and the loss of frequency resolution.

Disclosed herein are systems and methods for deep spectroscopic imaging of a biological sample. In an aspect, a system includes a broad bandwidth light source configured to generate an illumination beam, an interferometer, and a spectrometer. The interferometer includes a first beam splitter configured to split the illumination beam into an incident beam and a reference beam; an optical lens directs the incident beam onto a biological sample at a predefined offset from corresponding optical axis, and receive a beam scattered from the biological sample. The beams are configured to intersect with each other within a focal zone of the optical lens. Photons of the incident beam undergo multiple forward scattering within the biological sample. A second beam splitter configured to receive and superimpose the scattered and reference beams, to generate an interference beam. The spectrometer uses a spectral domain detection technique to assess tissue properties of the biological sample.

An apparatus for performing Raman spectral analysis of a sample is described, comprising a coherent light source, an first optical chain to direct the coherent light to impinge on the sample, a second optical chain to direct the scattered light onto a diffraction grating, and a third optical chain to direct the diffracted light onto detection array. The diffraction grating is a stairstep with a metalized surface, and a plurality of metalized stripes on a flat surface is disposed in a direction orthogonal to the long dimension of the stairsteps. The region between the flat surface and the stairstep is transparent. The zeroth-order fringe is selected by a slit and directed onto camera. The resultant interferogram is Fourier transformed to produce a representation of the Raman spectrum.

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.

The present application in some embodiments relates to methods for reducing noise and/or clutter when measuring a spectrum, particularly but not only for OCT imaging. In some embodiments a light source is synchronized with a detector. For example a narrow band light source is synchronized with a narrow band detector. For example, the light source may scan over multiple frequency bands and/or the detector may be tuned to a frequency band synergetic to the band of the light source. For example the light source and detector may be tuned to overlapping narrow bands. Optionally the detector has a sensor set for each frequency band. Optionally some sensor sets are individually resettable. For example each set may have a reset circuit. For example, a sensor set for a band not currently being measured is deactivated.

A spectrometer includes an interferometer having a first interference arm and a second interference arm to produce interference patterns from incident light. At least one of the interference arms includes a series of cascaded optical switches connected by two (or more) waveguides of different lengths. Each optical switch directs the incident light into one waveguide or another, thereby changing the optical path length difference between the first interference arm and the second interference arm. This approach can be extended to multi-mode incident light by placing parallel interferometers together, each of which performs spectroscopy of one single mode in the multi-mode incident light. To maintain the compactness of the spectrometer, adjacent interferometers can share one interference arm.