G01B9/02044

Interferometry with pixelated color discriminating elements combined with pixelated polarization masks

A pixelated color mask is combined with a pixelated polarization mask in dynamic interferometry. The color mask includes a wavelength-selective bandpass filter placed in front of each camera pixel such that each set of contiguous four camera pixels is covered by two green bandpass filters, a red bandpass filter, and a blue bandpass filter. The pixelated phase mask is coupled to the color filters such that one polarization filter covers one set of color filters. At least three polarization filters are used to calculate phase. In addition, the color signals can be used, for example, to encode the motion of the interferometer, to provide very high speed autofocus or tip/tilt feedback, to create a color image of the object being measured, to automatically focus the system at different positions for different measurements conducted with different color sources, and to perform heterodyne interferometry with a single, vibration-immune measurement.

SYSTEMS, METHODS, AND MEDIA FOR MULTIPLE REFERENCE ARM SPECTRAL DOMAIN OPTICAL COHERENCE TOMOGRAPHY

In some embodiments, systems, methods, and media for multiple reference arm spectral domain optical coherence tomography are provided which, in some embodiments, includes: a sample arm coupled to a light source; a first reference arm having a first path length; a second reference arm having a longer second path length; a first optical coupler that combines light from the sample arm and the first reference arm; a second coupler that combines light from the sample arm and the second reference arm; and an optical switch comprising: a first input port coupled to the first optical coupler; a second input coupled to the second coupler via an optical waveguide that induces a delay at least equal to an acquisition time of an image sensor; and an output coupled to the image sensor.

Imaging Systems with Improved Accuracy and Measurements
20220167843 · 2022-06-02 ·

A system for providing accurate lateral mapping of images acquired via a scanning mechanism has a modulator synced to the imaging engine clock to generate image markers. The markers are then used to remove distortions and generate spatially-accurate mapping. A method of correcting image distortions by identifying the modulations and removing the distortions according to the spacing of the modulations. The system and the method applicable to ocular biometry and topography with the inclusion of an OCT arrangement to image the whole eye while the traversing the cornea and retina simultaneously, and with the inclusion of an on-axis imaging system to evaluate the quality of the ocular surface.

OPTICAL COHERENCE TOMOGRAPHY DEVICE
20230273010 · 2023-08-31 · ·

This optical interference tomographic imaging device includes: a wavelength-sweeping laser light source; a merged light generation means that branches the laser light into two branched lights, and outputs merged light; a branching means that branches the merged light into object light and reference light; an irradiation means that irradiates a prescribed scanning range of an object being measured with the object light; a light receiver that generates information relating to the change in intensity ratio of interference light between the reference light and the object light scattered from the object being measured; and a control means that, on the basis of the information generated by the light receiver, acquires depth-direction structure data pertaining to the object being measured.

Optical coherence tomography with dispersed structured illumination
11725927 · 2023-08-15 · ·

Apparatus and methods are presented for enhancing the acquisition speed or performance of Fourier domain optical coherence tomography. In preferred embodiments a plurality of wavelength combs containing interleaved selections of wavelengths from a multi-wavelength optical source are generated and projected onto a sample. In certain embodiments the wavelength combs are projected simultaneously onto a plurality of regions of the sample, while in other embodiments the wavelength combs are projected sequentially onto the sample. Light in the wavelength combs reflected or scattered from the sample is detected in a single frame of a sensor array, and the detected light processed to obtain a tomographic profile of the sample. In preferred embodiments the wavelength comb generator comprises a wavelength interleaver in the form of a retro-reflective prism array for imparting different displacements to different selections of wavelengths from the optical source.

Interferometry with pulse broadened diode laser

Various optical systems equipped with diode laser light sources are discussed in the present application. One example system includes a diode laser light source for providing a beam of radiation. The diode laser has a spectral output bandwidth when driven under equilibrium conditions. The system further includes a driver circuit to apply a pulse of drive current to the diode laser. The pulse causes a variation in the output wavelength of the diode laser during the pulse such that the spectral output bandwidth is at least two times larger the spectral output bandwidth under the equilibrium conditions.

Swept frequency photonic integrated circuit for absolute metrology
11320255 · 2022-05-03 · ·

A digital measuring device implemented on a photonic integrated circuit, the digital measuring device including a tunable laser source implemented on the photonic integrated circuit configured to sweep over a frequency range to provide multi-wavelength light, a first waveguide structure implemented on the photonic integrated circuit configured to direct a first portion of light from the laser source at a moving object and receive light reflected from the moving object, a second waveguide structure implemented on the photonic integrated circuit configured to combine a second portion of light from the laser source with the light reflected from the moving object to produce a measurement beam, and a first detector implemented on the photonic integrated circuit configured to detect intensity values of the measurement beam to measure a distance between the digital measuring device and the moving object.

Spectroscopic measuring apparatus and method, and method for fabricating semiconductor device using the measuring method

A spectroscopic measuring apparatus and method are provided. The apparatus includes a first light source, object, microlens, and imaging lenses, an optical fiber, a spectrometer and a position controller. The object lens to allows light from the first light source to be incident on a stage configured to support a measurement object. The microlens is disposed between the object lens and the stage. The imaging lens images light reflected from the measurement object. The optical fiber has an input terminal disposed on a first image plane of the imaging lens. The spectrometer is disposed at an output terminal of the optical fiber. The position controller controls positions of the object lens, the microlens, and the optical fiber, and adjusts the position of the object lens so that a focus of the object lens is positioned at a virtual image position of a virtual image generated by the microlens.

Microresonator-Frequency-Comb-Based Platform For Clinical High-Resolution Optical Coherence Tomography

A method of providing optical coherence tomography (OCT) imaging may comprise using an on-chip frequency comb source interfaced with an OCT system by a circulator as an imaging source and reconstructing OCT images from resulting spectral data from target tissue illuminated by the imaging source.

APPARATUS, SYSTEMS, AND METHODS FOR DETECTING LIGHT
20220026193 · 2022-01-27 ·

Systems or apparatuses may include a spatial modulator for spatially modulating light to produce spatially modulated light, a dispersing element for dispersing the modulated light to produce spatially modulated and dispersed light, a polarization-sensitive displacement element for providing a polarization dependent displacement of the dispersed light, and a detector for detecting the spatially modulated, dispersed and displaced light. The system and/or apparatus may include a broadband light source for providing broadband light, a linear polarizer for polarizing the broadband light, a double path interferometer including a sample path via the object and a reference path, a beam splitter for superposing a portion of the light from the sample path and a portion of the light from the reference path to create superposed light for spatial modulation, and/or a processor for processing an output of the detector to produce a three-dimensional image of the object.