A Fourier spectroscopic analyzer includes: a first light source that emits light including a wavelength component in a first wavelength band which is a wavelength band in which a spectrum of light passing through a sample is acquired and a wavelength component in a second wavelength band different from the first wavelength band; a second light source that emits light including the wavelength component in the second wavelength band; an interferometer that acquires an interferogram which is coherent light from the light emitted from the first light source; a first light coupling optical system that couples light emitted from the second light source to at least one of light emitted from the first light source and the interferogram acquired by the interferometer; a light receiver that outputs a first light-reception signal acquired by receiving light including the wavelength component in the first wavelength band out of the wavelength components included in the light passing through the sample and a second light-reception signal acquired by receiving light including the wavelength component in the second wavelength band; and a signal processor that performs a Fourier transform process on the first light-reception signal and the second light-reception signal to acquire a spectrum of the wavelength component in the first wavelength band with noise removed therefrom.

A spectrophotometer includes: an infrared light source; an interferometer; a first detector; and a monitor unit. The monitor unit includes: a second detector; and a light amount control unit. The light amount control unit is operable to control the infrared light source such that the amount comes closer to a target light amount, based on the signal. The infrared light source emits light having a first wavelength range and light having a second wavelength range different from the first wavelength range. The second detector includes: a first light detection element; and a second light detection element. The first light detection element outputs to the light amount control unit a first voltage corresponding to the light having the first wavelength range. The second light detection element outputs to the light amount control unit a second voltage corresponding to the light having the second wavelength range.

A Fourier spectroscopic analyzer includes: a first light source that emits light including a wavelength component in a first wavelength band which is a wavelength band in which a spectrum of light passing through a sample is acquired and a wavelength component in a second wavelength band different from the first wavelength band; a second light source that emits light including the wavelength component in the second wavelength band; an interferometer that acquires an interferogram which is coherent light from the light emitted from the first light source; a first light coupling optical system that couples light emitted from the second light source to at least one of light emitted from the first light source and the interferogram acquired by the interferometer; a light receiver that outputs a first light-reception signal acquired by receiving light including the wavelength component in the first wavelength band out of the wavelength components included in the light passing through the sample and a second light-reception signal acquired by receiving light including the wavelength component in the second wavelength band; and a signal processor that performs a Fourier transform process on the first light-reception signal and the second light-reception signal to acquire a spectrum of the wavelength component in the first wavelength band with noise removed therefrom.

A new spectral measurement technique is provided which enables measurement even if the light to be measured exists for a very short period. In one embodiment, a broadband pulsed light wave whose wavelength shifts temporally and continuously in a pulse interferes with a light wave to be measured. The intensity at each wavelength of the light wave to be measured is obtained using a Fourier transform of the output signal from a detector that has detected the intensity of the wave resulting from the interference. A laser beam from a laser source is converted to a supercontinuum wave by a nonlinear optical element, and a pulse extension element extends pulses of the supercontinuum wave, thus generating the broadband pulsed light wave.

Diffuse reflectance spectroscopy apparatus for use in analysing a sample comprising a sample receiving location 2 for receiving a sample 3 for analysis; an illumination arrangement 4 for directing light towards a received sample; a detector 6 for detecting light reflected by a received sample; and collection optics 5 for directing light reflected by a received sample towards the detector. The illumination arrangement further comprises an interferometer 42 and a half beam block 45a, 45b which is disposed substantially at a focus in the optical path for blocking light which exits the interferometer, passes said focus, and is reflected from re-entering the interferometer. A half beam block 45a may be disposed in the optical path between the interferometer and the light source 41 for blocking light that exits the interferometer back towards the light source and is reflected by the light source from re-entering the interferometer and/or a half beam block 45b may be disposed in the optical path on the opposite side of the interferometer than the light source.

In a Fourier-transform spectroscopy apparatus, a scanning mirror is arranged on a light path of scanning light. The scanning mirror delays or advances the scanning light with respect to reference light according to the rotational angle of the scanning mirror from its initial position. A spectroscopic spectrum generating unit generates an interferogram based on the intensity of the detection target light obtained from the detection target, and Fourier transforms the interferogram thus generated. The spectroscopic spectrum generating unit corrects the nonlinearity of the group delay between an envelope of the reference light and an envelope of the scanning light, and corrects the nonlinearity of the phase shift between the respective envelopes.

Aspects of the disclosure relate to a self-referenced spectrometer for providing simultaneous measurement of a background or reference spectral density and a sample or other spectral density. The self-referenced spectrometer includes an interferometer optically coupled to receive an input beam and to direct the input beam along a first optical path to produce a first interfering beam and a second optical path to produce a second interfering beam, where each interfering beam is produced prior to an output of the interferometer. The spectrometer further includes a detector optically coupled to simultaneously detect a first interference signal produced from the first interfering beam and a second interference signal produced from the second interfering beam, and a processor configured to process the first interference signal and the second interference signal and to utilize the second interference signal as a reference signal in processing the first interference signal.

A new apparatus and method within a portable Mudlogging gas detection system that determines the total amounts and various composition of an incoming mix of gases extracted from drilling fluid. The Mudlogging system consists of at least one electronic computing device, at least one infrared interferometer, and at least one other device for detecting gasses extracted from the drilling fluid. The Mudlogging system may switch from the primary gas detection means to a secondary gas detection means upon detection of a non-recoverable fault of the first gas detection means.

This document describes techniques and devices for Fourier-transform infrared (FT-IR) spectroscopy using a mobile device. A mobile device (502) includes a light source (504) that emits light toward an interferometer (508) that uses mirrors to separate and recombine the light. The interferometer directs the recombined light toward a person. Light reflected from, or transmitted through, the person is received through a reception port (506) to a photodetector (510) that outputs photodetector data that corresponds to a measured light intensity of the reflected and transmitted light as a function of a path length of the light or a mirror position of the interferometer. Based on the photodetector data, an interferogram is generated. Applying a technique such as a Fourier transform to the interferogram, a spectrum data set of the reflected and transmitted light is generated. Based on the spectrum data set, a concentration of solutes in the person's blood is calculated.

An apparatus for providing a variable sized aperture for an imaging device includes a first plate having a first plurality of plate apertures extending therethrough and a second plate having a second plurality of plate apertures extending therethrough. A first motor is operably connected to the first plate and a second motor is operably connected to the second plate. The first and second motors are configured to move the first plate and the second plate with respect to one another so as to align any of the first plurality of plate apertures with any of the second plurality of plate apertures to define a plurality of light beam apertures.