Apparatus and methods for spectral analysis of a sample are described, for example for carrying out Raman or other optical or spectroscopic analysis of samples such as pharmaceutical dosage forms, including oral solid dosage forms such as tablets or capsules. Such apparatus may comprise delivery optics arranged to direct probe light to a delivery region of the sample, collection optics arranged to collect probe light scattered from a collection region of the sample, and a spectrometer having an entrance port, the spectrometer being arranged to receive the collected probe light from the collection optics at the entrance port of the spectrometer, and to detect spectral features in the received probe light. In particular, the collection optics may comprise Koehler integration optics arranged to process the collected probe light such that the collected light from each point of the collection region is distributed across the entrance port of the spectrometer.

Swept-source Raman spectroscopy uses a tunable laser and a fixed-wavelength detector instead of a spectrometer or interferometer to perform Raman spectroscopy with the throughput advantage of Fourier transform Raman spectroscopy without bulky optics or moving mirrors. Although the tunable laser can be larger and more costly than a fixed wavelength diode laser used in other Raman systems, it is possible to split and switch the laser light to multiple ports simultaneously and/or sequentially. Each site can be monitored by its own fixed-wavelength detector. This architecture can be scaled by cascading fiber switches and/or couplers between the tunable laser and measurement sites. By multiplexing measurements at different sites, it is possible to monitor many sites at once. Moreover, each site can be meters to kilometers from the tunable laser. This makes it possible to perform swept-source Raman spectroscopy at many points across a continuous flow manufacturing environment with a single laser.

A small, handheld Raman spectrometer device can be built from a laser, lenses, and a diffraction grating configured in a right-angle Raman spectroscopy geometry, and used in conjunction with a cell-phone camera to record the Raman spectra. The cell-phone-based Raman spectrometer system is suited to performing in-situ measurements of chemical and biological molecules.

Optical spectrometers may be used to determine the spectral components of electromagnetic waves. Spectrometers may be large, bulky devices and may require waves to enter at a nearly direct angle of incidence in order to record a measurement. What is disclosed is an ultra-compact spectrometer with nanophotonic components as light dispersion technology. Nanophotonic components may contain metasurfaces and Bragg filters. Each metasurface may contain light scattering nanostructures that may be randomized to create a large input angle, and the Bragg filter may result in the light dispersion independent of the input angle. The spectrometer may be capable of handling about 200 nm bandwidth. The ultra-compact spectrometer may be able to read image data in the visible (400-600 nm) and to read spectral data in the near-infrared (700-900 nm) wavelength range. The surface area of the spectrometer may be about 1 mm.sup.2, allowing it to fit on mobile devices.

A downhole tool has a tool body with an outer diameter equal to a borehole diameter, at least one cavity formed in and opening to an outer surface defining the outer diameter of the tool body, a light source, a filter, and a light detector mounted in the at least one cavity, and a window disposed at the opening of the at least one cavity, wherein the window encloses the cavity.

An optical sensing module suitable for wearable devices, the optical sensing module comprising: a silicon or silicon nitride transmitter photonic integrated circuit (PIC), the transmitter PIC comprising: a plurality of lasers, each laser of the plurality of lasers operating at a wavelength that is different from the wavelength of the others; an optical manipulation region, the optical manipulation region comprising one or more of: an optical modulator, optical multiplexer (MUX); and additional optical manipulation elements; and one or more optical outputs for light originating from the plurality of lasers.

A handheld Surface-Enhanced Raman Spectroscopy (SERS) device for detecting phenylalanine (Phe) in a sample collected from a subject, the device comprising a laser generator configured to produce a laser beam; a nanoporous anodic aluminum oxide (NAAO) substrate configured to receive the sample collected from the subject; and a light sensor configured to receive a light.

Systems and methods for measuring temperature in an environment by creating a first beam having an energy of about 50 mJ/pulse, and a pulse duration of about 100 ps. A second beam is also created, having an energy of about 2.3 mJ/pulse, and a pulse duration of about 58 ps. The first beam and the second beam are directed into a probe region, thereby expressing an optical output. Properties of the optical output are measured at a sampling rate of at least about 100 kHz, and temperature measurements are derived from the measured properties of the optical output. Such systems and methods can be used to measure temperature in environments exhibiting highly turbulent and transient flow dynamics.

A system for real-time assessment of systemic hydration includes a light source configured to operably emit light of first and second wavelengths; means for delivering the emitted light to a target site to excite at least one first spot at the target site, and collecting Raman scattering light scattered from the target site at a plurality of second spots; a detector coupled with said means for obtaining a plurality of spatially offset Raman spectra from the collected Raman scattering light, each spatially offset Raman spectrum corresponding to a respective second spot of the target site and associated with a depth of tissues at which the Raman scattering light is scattered; and a controller configured to process the plurality of spatially offset Raman spectra so as to identify spectral features from the plurality of spatially offset Raman spectra, and assess systemic hydration from the identified spectral features.

A method, a system, and a non-transitory computer readable medium for accurate Raman spectroscopy. The method may include executing at least one iteration of the steps of: (i) performing, by an optical measurement system, a calibration process that comprises (a) finding a misalignment between a region of interest defined by a spatial filter, and an impinging beam of radiation that is emitted from an illuminated area of a sample, the impinging beam impinges on the spatial filter; and (b) determining a compensating path of propagation of the impinging beam that compensates the misalignment; and (ii) performing a measurement process, while the optical measurement system is configured to provide the compensating path of propagation of the impinging beam, to provide one or more Raman spectra.