Provided are an optical spectrum analyzer and a pulse-modulated light measurement method capable of measuring pulse-modulated light even when a pulse-on time and a pulse period of the pulse-modulated light are unknown. Pulse-modulated light (DUT) is incident on a diffraction grating 3. A first light receiving unit 8 receives the 0th-order light of diffracted light diffracted by the diffraction grating 3. A second light receiving unit 7 receives diffracted light of an order other than the 0th-order light. A measurement timing signal generation unit 9 generates a sampling signal based on the 0th-order light received by the first light receiving unit. The spectrum of the diffracted light received by the second light receiving unit is measured based on the sampling signal generated by the measurement timing signal generation unit.

An optical spectrum analyzer (OSA) for measuring an optical spectrum of an input optical signal in a measurement wavelength range is provided. The OSA comprises a modulator, an integrated optical filter, and a photodetector. The modulator modulates the input optical signal by applying a dither modulation to facilitate detection and noise rejection. The integrated optical filter, which may include a ring resonator system, is sequentially tunable to selectively transmit each wavelength of the modulated optical signal in the measurement wavelength range. The photodetector sequentially detects each wavelength of the modulated optical signal in the measurement wavelength range to provide a representative output electrical signal.

Method of predicting a distribution of light in an illumination pupil of an illumination system includes identifying component(s) of the illumination system the adjustment of which affects this distribution and simulating the distribution based on a point spread function defined in part by the identified components. The point spread function has functional relationship with configurable setting of the illumination settings.

A spectrometer includes a light source that emits a beam into a sample volume comprising an absorbing medium. Thereafter, at least one detector detects at least a portion of the beam emitted by the light source. It is later determined, based on the detected at least a portion of the beam and by a controller, that a position and/or an angle of the beam should be changed. The beam emitted by the light source is then actively steered by an actuation element under control of the controller. In addition, a concentration of the absorbing media can be quantified or otherwise calculated (using the controller or optionally a different processor that can be local or remote). The actuation element(s) can be coupled to one or more of the light source, a detector or detectors, and a reflector or reflectors intermediate the light source and the detector(s).

A liquid-crystal based color switch for use with an image sensor having sub-diffraction-limited (SDL) pixels. The color switch may switch between a first mode where green light is passed (and blue and red light is blocked) and a second mode where blue and red light is passed (and green light is blocked). The color switch may include an achromatic switch (such as a liquid crystal switch) and retarder stack filter that are both sandwiched between a first and a second polarizer. The SDL pixels may be distributed so that green subpixels are never adjacent to other green subpixels in the same row or column, so that red subpixels are always adjacent to green subpixels in the same row or column, and so that blue subpixels are always adjacent to green subpixels in the same row or column.

A device is provided for combining two or more separate components of an optical analysis system, to use common entrance and exit apertures for optical measurements across a measurement space such as a stack, combustion chamber, duct or pipeline, in such way that the optical paths from the respective light sources to detectors are substantially the same, enabling multiple optical measurements over a single optical path or closely aligned optical paths with equivalent ambient conditions such as temperature and pressure distribution and background substance concentrations. The device and a set of interconnectable devices forming a modular system are useful, for example, in absorption spectroscopy, such as for measuring the amount fraction of the chemical constituents of a fluid in a measurement volume.

This is to provide a photometric apparatus improved in measurement precision by improving the state of light incident to a sensor, which photometric apparatus 1 comprises a photometric sensor 30 into which light which is an object to be measured is incident, a signal processing means for processing a sensor output by the photometric sensor, and optical systems 50, 100, 92, 93 and 150 which introduces external light into the photometric sensor, wherein a columnar fiber rod 100 in which a center axis is provided along a direction perpendicular to a light receiving surface of the photometric sensor is provided at a part of the optical system.

Devices and methods to perform Raman spectroscopy with a structured excitation profile to obtain a Raman excitation map. A device includes a broadband light source to emit a broadband light beam and excitation optics to disperse the broadband light beam to strike a sample as incident light according to a structured excitation profile. The device further includes analysis optics to collect scattered light scattered by the incident light striking the sample, block Rayleigh scatter from the collected scattered light in a manner complementary to the structured excitation profile, and direct Raman scatter from the collected scattered light to a sensor to generate a signal to form a Raman excitation map.

An optical module 1 includes: a mirror unit 2 including a base 21, a movable mirror 22, and a fixed mirror 16; a beam splitter unit 3 that is disposed on one side of the mirror unit 2 in a Z-axis direction; a light incident unit 4 that causes measurement light L0 to be incident to the beam splitter unit 3; a first light detector 6 that is disposed on the one side of the beam splitter unit 3 in the Z-axis direction, and detects interference light L1 of measurement light which is emitted from the beam splitter unit 3; a support 9 to which the mirror unit 2 is attached; a first support structure 11 that supports the beam splitter unit 3; and a second support structure 12 that is attached to the support 9 and supports the first light detector 6.

To implement a configuration for enabling independent adjustment of a spatial resolution and a wavelength resolution of a spectroscopic measurement device. A spatial resolution adjustment unit configured to adjust a spatial resolution of the spectroscopic measurement device, and a wavelength resolution adjustment unit configured to adjust a wavelength resolution of the spectroscopic measurement device are included, and the spatial resolution adjustment unit maintains output light from a condensing unit to a spectroscopic imaging unit of the spectroscopic measurement device as parallel light, adjusts a parameter of a constituent element of the condensing unit, and changes the spatial resolution without changing the wavelength resolution of the spectroscopic measurement device. The wavelength resolution adjustment unit adjusts a parameter of a spectroscopic imaging unit of the spectroscopic measurement device and changes the wavelength resolution without changing the spatial resolution of the spectroscopic measurement device.