Spectrometers include an optical assembly with optical elements arranged to receive light from a light source and direct the light along a light path to a multi-element detector, dispersing light of different wavelengths to different spatial locations on the multi-element detector. The optical assembly includes: (i) a collimator arranged in the light path to receive the light from the light source, the collimator including a mirror having a freeform surface; (2) a dispersive sub-assembly including an echelle grating, the dispersive sub-assembly being arranged in the light path to receive light from the collimator; and (3) a Schmidt telescope arranged in the light path to receive light from the dispersive sub-assembly and focus the light to a field, the multi-element detector being arranged at the field.

Apparatuses for collection of upstream and downstream transmission electron microscopy (TEM) cathodoluminescence (CL) emitted from a sample exposed to an electron beam are described. A first fiber optic cable carries first CL light emitted from a first TEM sample surface, into a spectrograph. A second fiber optic cable carries second CL light emitted from a second TEM sample surface into the spectrograph. The first and second fiber optic cables are positioned such that the spectrograph produces a first light spectrum for the first fiber optic cable and a separate light spectrum for the second fiber optic cable. The described embodiments allow collection of TEM CL data in a manner that allows analyzing upstream and downstream TEM CL signals separately and simultaneously with an imaging spectrograph.

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.

A spectroscopic analysis system includes a light source including a light emitting diode (51X), a wavelength converter (52X) configured to convert a wavelength of light output from the light emitting diode (51X), and a condenser (54X) configured to condense light output from the wavelength converter (52X), the light source including a mixing section configured to mix light output from the plurality of light emitting elements, and the wavelength of the light output from the plurality of light emitting elements being different, and a spectroscopic measurement section configured to acquire spectroscopic data by dispersing light reflected from an object on which the light source emits the light.

A radiation detection technique employs field enhancing structures and electroluminescent materials to converts incident Terahertz (THz) radiation into visible light and/or infrared light. In this technique, the field-enhancing structures, such as split ring resonators or micro-slits, enhances the electric field of incoming THz light within a local area, where the electroluminescent material is applied. The enhanced electric field then induces the electroluminescent material to emit visible and/or infrared light via electroluminescent process. A detector such as avalanche photodiode can detect and measure the emitted light. This technique allows cost-effective detection of THz radiation at room temperatures.

A spectrometer system may be used to determine one or more spectra of an object, and the one or more spectra may be associated with one or more attributes of the object that are relevant to the user. While the spectrometer system can take many forms, in many instances the system comprises a spectrometer and a processing device in communication with the spectrometer and with a remote server, wherein the spectrometer is physically integrated with an apparatus. The apparatus may have a function different than that of the spectrometer, such as a consumer appliance or device.

The use of a transdermal Raman spectrum to measure glucose or other substance concentration can give an inaccurate result if the Raman signals originate at a wrong skin depth. To predict whether a spectrum of Raman signals received transdermally in a confocal detector apparatus and having at least one component expected to have an intensity representing the concentration of glucose or another skin component at a point of origin of the Raman signals below the surface of the skin will accurately represent the concentration, peaks in the spectrum at 883/4 cm.sup.−1 and 894 cm.sup.−1 are measured to determine whether the Raman signals originate primarily within the stratum corneum so that the spectrum will be less likely to represent the concentration accurately or originate primarily below the stratum corneum so that the spectrum will be more likely to represent the concentration accurately.

Systems and methods for determining one or more properties of a sample are disclosed. The systems and methods disclosed can be capable of measuring along multiple locations and can reimage and resolve multiple optical paths within the sample. The system can be configured with one-layer or two-layers of optics suitable for a compact system. The optics can be simplified to reduce the number and complexity of the coated optical surfaces, et al. on effects, manufacturing tolerance stack-up problems, and interference-based spectroscopic errors. The size, number, and placement of the optics can enable multiple simultaneous or non-simultaneous measurements at various locations across and within the sample. Moreover, the systems can be configured with an optical spacer window located between the sample and the optics, and methods to account for changes in optical paths due to inclusion of the optical spacer window are disclosed.

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 is provided that can separate measurement target light into orthogonal polarization components and perform measurement and enable optical spectrum measurement that does not depend on polarization of the measurement target light. Measurement target light is separated into two orthogonal polarization components, the two polarization components whose position is shifted in an engraved line direction of a diffraction grating are incident on the diffraction grating, diffracted light of the two polarization components emitted from the diffraction grating is condensed, and the condensed diffracted light is incident on an incident side end surface of a 2-core ferrule with the two polarization components adjacent to each other.