Abstract: A compact handheld optical coherence tomography (OCT) spectrometer according to an embodiment of the present disclosure includes: a spectrometer optical module; a sensor board coupled to one side of the spectrometer optical module and including a sensor that converts light received from the spectrometer optical module into an electrical signal; and a connector configured to supply, to the sensor board, a control signal and a power signal received from another circuit outside the spectrometer and to transmit a signal received from the sensor board to another external circuit, and the sensor board is packaged with the spectrometer optical module, and the sensor is not indented but is formed to protrude from the surface of the sensor board, and a light receiving portion of the sensor is configured to face the inside of the packaged component and collect light from the spectrometer optical module.

Abstract: An interferometric measurement system includes ports configured to receive an optical signal from an optical source and an optical signal from a target. A photonic integrated circuit includes a variable delay configured to select between at least two optical paths from the input to an output such that the optical signal from the optical source passes to the output while experiencing an optical delay based on a selected one of the at least two optical paths where a loss of the optical signal from the optical source provided to the input that passes to the output is nominally the same for each of the at least two optical paths. An optical receiver is configured to receive the optical signal from the target and to receive the optical signal from the optical source that experiences the optical delay based on the selected one of the at least two optical paths and generates a corresponding electrical receive signal at an electrical output.

Abstract: Embodiments of systems and methods for measuring a surface topography of a semiconductor structure are disclosed. In certain examples, a plurality of interference signals, each corresponding to a respective one of a plurality of positions on a surface of the semiconductor structure, are measured. Calibration signals, associated with a baseline region corresponding to a first category of a plurality of categories and a calibrated region corresponding to a second category of the plurality of categories, are measured. A surface height offset, associated with the baseline region and the calibrated region, is determined based on original surface heights and the calibration signals. The original surface heights are determined based on the plurality of interference signals corresponding to the baseline region and the calibrated region. The surface topography of the semiconductor structure is characterized based, at least in part, on the surface height offset and the original surface heights.

Abstract: There is described a method for performing a Raman spectroscopy measurement on a sample. The method generally has sequentially illuminating an area of said sample with first and second excitation signals, said first excitation signal being slightly spectrally spaced-apart from said second excitation signal, resulting in said area sequentially emitting first and second emission signals; upon receiving said first emission signal, measuring a first intensity value being indicative of optical intensity of said first emission signal within at least a detection band; upon receiving said second emission signal, measuring a second intensity value being indicative of optical intensity of said second emission signal within said detection band; and performing said Raman spectroscopy measurement by comparing said first intensity value to said second intensity value.

Abstract: Disclosed is a surface sensing apparatus, one embodiment having a source of coherent radiation capable of outputting wavelength emissions to create a first illumination state to illuminate a surface and create a first speckle pattern, an emission deviation facility capable of influencing the emission to illuminate the surface and create a second illumination state and a second speckle pattern, and a sensor capable of sensing a representation of the first and a second speckle intensity from the first and second speckle pattern. Also disclosed are methods of sensing properties of the surface, one embodiment comprising the steps of illuminating the surface having a first surface state with the source of coherent radiation emission, sensing a first speckle intensity from the surface, influencing a relationship of the surface to the emission to create a second surface state and sensing a second speckle intensity from the surface at the second surface state.

Abstract: An OCT axial length measurement device is configured to measure an area of the retina within a range from about 0.05 mm to about 2.0 mm. The area can be measured with a scanned measurement beam or plurality of substantially fixed measurement beams. The OCT measurement device may comprise a plurality of reference optical path lengths, in which a first optical path length corresponds to a first position of a cornea, and a second optical path length corresponds to a second position of the retina, in which the axial length is determined based on a difference between the first position and the second position. An axial length map can be generated to determine alignment of the eye with the measurement device and improve accuracy and repeatability of the measurements. In some embodiments, the OCT measurement device comprises a swept source vertical cavity surface emitting laser (“VCSEL”).

Abstract: A method for reproducing a lumen curve to a given tolerance in at least one image in optical coherence tomography (OCT). Examples of applications include imaging, evaluating and diagnosing biological objects, such as, but not limited to, cardio applications, and being obtained via one or more optical instruments, such as, but not limited to, catheters. The method may include obtaining a set of original points of the curve that correspond to measurements from an optical imaging device. Filtering the set of original points using at least one criteria to obtain a subset of original points. The method may also include determining if the subset of original points is less than a predetermined threshold and adjusting the at least one criteria to increase an amount of original points included in the subset of original points when it is determined that the subset of original points is less than the predetermined threshold.

Abstract: A metrology frame configured to receive and secure a workpiece in preparation for an interferometric determination of a spatial profile of the workpiece with the use of one or more retroreflectors removably cooperated with the frame in known pre-determined spatial relationship with respect the fiducial features of not only the workpiece but those of the metrology frame itself. The metrology frame is necessarily devoid of a holographic optical element, while the measurement apparatus containing such metrology frame employs a hologram configured to generate at least one alignment optical wavefront that spatially converges on the retroreflector.

Abstract: A gas analysis system with an FTIR spectrometer preferably utilizes a long path gas cell, a narrow band detector, and an optical filter that narrows the detection region to measure hydrogen sulfide.

Abstract: A fast measurement method for micro-nano deep groove structure based on white light interference, including: establishing a white light interference system, using the white light interference system to measure the structure of the groove, the CCD camera collects and obtains multiple groups of groove interferograms and the serial number corresponding to each groove interferogram in each group; processing each group of groove interferograms of the groove sample to obtain the maximum contrast of each group of groove interferograms and the 3D reconstruction diagram of the local structure; extracting the interface reconstruction diagram in the 3D reconstruction diagram of the local structure according to each group of the groove interferograms; after splicing the interface reconstruction diagrams corresponding to all groups of groove interferograms, obtaining a 3D structural reconstruction diagram of the groove sample, and measuring the depth and width of the groove sample according to the 3D structural reconstruc

Abstract: 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.

Abstract: A system for processing Raman scattering light from a sample is provided. The system includes a source, a digital mirror device (DMD), a detector, and an analyzer. The DMD is configured to reflect Raman scattering light and includes micromirrors selectively controllable between ON and OFF states. The detector is configured to detect Raman scattering light and to produce signals representative of the Raman scattering light. The analyzer is in communication with the light source, the DMD, the detector, and a memory storing instructions, which instructions when executed cause the processor to: a) control the light source to produce a beam of light for interrogating the sample; b) control the DMD to place in an ON or OFF state based on one or more known spectral shapes stored in the memory; and c) process the Raman scattering light reflected by the micromirrors in the ON state.

Abstract: A method of optical analysis comprises receiving light at an optical spectrometer module from a light source, distributing the received light into two or more light beams with a light distribution component of the optical spectrometer module, concurrently exposing each of a reference and one or more test samples to one of the two or more light beams, and concurrently measuring a property of the light associated with each of the reference sample and one or more test samples with a corresponding detector.

Abstract: A displacement sensor includes a radiation part that irradiates a workpiece displaceable in a predetermined displacement direction with light, a light receiving part that receives a reflected light generated when the light radiated by the radiation part is reflected on the workpiece, and a fringe generation part that includes a generation means for generating fringes on a light receiving surface of the light receiving part when the light receiving part receives the reflected light from the workpiece. The fringe generation part and the light receiving part are arranged such that the fringe generation part and the light receiving part are parallel to the displacement direction, or parallel to a virtual image of the displacement direction.

Abstract: This disclosure presents a process and system to determine characteristics of a subterranean formation proximate a borehole. Borehole material is typically pumped from the borehole, though borehole material can be used within the borehole as well. Extracted material of interest is collected from the borehole material and prepared for analyzation. Typically, the preparation can be a separation process, a filtering process, a moisture removal process, a pressure control process, a flow control process, a cleaning process, and other preparation processes. The prepared extracted material is placed in a laser dispersion spectroscopy device (LDS) where measurements can be taken. A LDS analyzer can generate results utilizing the measurements, where the results of the extracted material can include one or more of composition parameters, alkene parameters, and signature change parameters. The results can be communicated to other systems and processes to be used as inputs into well site operation plans and decisions.

Abstract: Apparatus and method for detecting wavefront aberration of an objective lens, comprising a wavefront detection system, a planar mirror, and a planar mirror adjusting mechanism; the objective lens is placed between planar mirror and wavefront detection system; planar mirror is positioned at focal point of the objective lens. A test wavefront emitted by wavefront detection system passes through the objective lens, gets reflected by the planar mirror, and t passes through the objective lens again; the wavefront detection system receives and detects the test wavefront to derive a phase distribution thereof; an angle of the planar mirror tilts at is adjusted to obtain different return wavefronts; a polynomial for expressing wavefront aberration is selected, and expressions corresponding to all the return wavefronts are calculated; result of fitting the wavefront aberration of the objective lens when expressed by the selected polynomial is derived through fitting with the polynomial.

Abstract: An OCT examination device for recording an object comprises an OCT radiation source which emits OCT radiation, an OCT beam path, a housing, an exit opening formed in the housing for the OCT radiation of the OCT radiation source, an OCT exit direction of the radiation through the exit opening, a control unit connected to the OCT radiation source OCT radiation and configured to record a multiplicity of measurement profiles mutually separated in a recording period and, within the recording period, to drive the OCT radiation source in order to emit the OCT radiation and the OCT radiation receiver in order to receive the backscattered OCT radiation, and to keep an OCT output direction and an OCT exit direction constant with respect to one another in their angular orientation during the recording period.

Abstract: Systems and methods for bacterial load sensing devices are disclosed. An example contamination sensing device may comprise a body, a light emitter disposed on the body and configured to emit an excitation wavelength of light toward a surface, a sensor disposed on the body, configured to detect light, and directed toward the surface, and a filter adjuster configured to determine, based on the excitation wavelength of light, a filter configured to remove light outside of an emission wavelength range, wherein the emission wavelength range corresponds to wavelengths of light emitted by contamination upon exposure to the excitation wavelength of light, and adjustably move the filter in front of the sensor.

Abstract: An ophthalmic imaging system including an ocular lens and an optical coherence tomography (OCT) imaging module is provided. The OCT imaging module is able to image both retina and anterior segment of eyes by switching a lens group into and out of the OCT light path. The OCT imaging module includes a retina imaging mode and an anterior segment imaging mode. In the retina imaging mode, there exists an intermediate image plane located between the ocular lens and the OCT imaging module. From the retina imaging mode, anterior segment imaging is achieved by inserting a switching lens group into the optical path inside the OCT imaging module or replacing the whole OCT imaging module of the retina mode, wherein, after the insertion, there exist a new intermediate image plane located inside the OCT imaging module and a conjugate of the entrance pupil of the OCT imaging module located between the ocular lens and the OCT imaging module.

Abstract: Systems and methods for unwrapping a phase map are disclosed. Such systems and methods may include receiving a wrapped phase map associated with an interferometric measurement of a sample including patterned features; removing a tilt from the wrapped phase map; generating a background; detecting features in the wrapped phase, the features in the wrapped phase map corresponding to least some of the patterned features of the sample; replacing phases of the features with the background at corresponding locations in the wrapped phase map; unwrapping the modified wrapped phase map using a global phase-unwrapping; applying local phase-unwrapping to restore the phases of the features; and reapplying the tilt to generate an output unwrapped phase map.