The present invention relates to an optical flow cell (1) for a measuring device, having an input light guide with a light exit surface, an output light guide with a light entrance surface, said input light guide and output light guide being integrated with a holder (30) to form optical flow cell (1), and wherein the holder (30) extends along a first axis (A) and has a through hole (31) for receiving a flow of a sample fluid, said through hole (31) being transversal to said first axis (A), and the input light guide and output light guide further are arranged in said holder (30) so that the light exit surface and the light entrance surface extend into said through hole (31) and are arranged to be in optical alignment with each other and at a first distance from each other. The invention also relates to a measuring device having at least one optical flow cell (1).

A method for determining the refractive index profile of a preform when the RIP is not substantially symmetrical. (i) The preform is scanned, starting with a first projection angle, and raw data are created representing the object through measured data. (ii) Optionally, the object is rotated and step (i) repeated iteratively until all projection angles have been scanned and all measured data have been created. (iii) The measured data are processed to form a sinogram and, if the optional step (ii) has been completed, the method proceeds to step (v). (iv) The object is rotated and steps (i) and (iii) are repeated iteratively until all projection angles have been scanned. (v) A 2D RIP is calculated. (vi) A line section of interest is selected within the 2D RIP. (vii) A fitting procedure is applied to the line section of interest. (viii) Finally, refractive index steps/gradients and dimensions are determined.

The application relates to a method of testing an item with a spectrally precise, artificial solar spectrum including wavelengths from 200 nm to 20 microns and it also relates to a solar spectrum simulator capable of producing a light spectrum including wavelengths from 200 nm to 20 microns. The simulator comprises: a) amplitude optimization software; b) a spectrum controller; c) an emitter controller; d) heat lamp/heater generation sources including: a xenon/infrared (IR) lamp and a blackbody radiator; e) laser generation sources including an ultraviolet (UV) laser source, a visible laser source, a near infrared (NIR) laser source, a short wavelength (SW) laser source, a medium wavelength (MW) laser source, a long wavelength (LW) laser source, and a quantum cascade laser source (QCL); f) a beam combiner; g) a beam profiler; h) a spectrometer; and i) a surface on which can be placed an item to be tested.

The application relates to a method of testing an item with a spectrally precise, artificial solar spectrum including wavelengths from 200 nm to 20 microns and it also relates to a solar spectrum simulator capable of producing a light spectrum including wavelengths from 200 nm to 20 microns. The simulator comprises: a) amplitude optimization software; b) a spectrum controller; c) an emitter controller; d) heat lamp/heater generation sources including: a xenon/infrared (IR) lamp and a blackbody radiator; e) laser generation sources including an ultraviolet (UV) laser source, a visible laser source, a near infrared (NIR) laser source, a short wavelength (SW) laser source, a medium wavelength (MW) laser source, a long wavelength (LW) laser source, and a quantum cascade laser source (QCL); f) a beam combiner; g) a beam profiler; h) a spectrometer; and i) a surface on which can be placed an item to be tested.

A spectroscopic assembly may include a spectrometer. The spectrometer may include an illumination source to generate a light to illuminate a sample. The spectrometer may include a sensor to obtain a spectroscopic measurement based on light, reflected by the sample, from the light illuminating the sample. The spectroscopic assembly may include a light pipe to transfer the light reflected from the sample. The light pipe may include a first opening to receive the spectrometer. The light pipe may include a second opening to receive the sample, such that the sample is enclosed by the light pipe and a base surface when the sample is received at the second opening. The light pipe may be associated with aligning the illumination source and the sensor with the sample.

A method for determining the refractive index profile of a preform when the RIP is not substantially symmetrical. (i) The preform is scanned, starting with a first projection angle, and raw data are created representing the object through measured data. (ii) Optionally, the object is rotated and step (i) repeated iteratively until all projection angles have been scanned and all measured data have been created. (iii) The measured data are processed to form a sinogram and, if the optional step (ii) has been completed, the method proceeds to step (v). (iv) The object is rotated and steps (i) and (iii) are repeated iteratively until all projection angles have been scanned. (v) A 2D RIP is calculated. (vi) A line section of interest is selected within the 2D RIP. (vii) A fitting procedure is applied to the line section of interest. (viii) Finally, refractive index steps/gradients and dimensions are determined.

An online monitoring device for CMP is arranged in a polishing disc, rotates with the polishing disc, and comprises: a light source; an optical lens set, configured to receive a light beam emitted by the light source and generate a collimated beam; a reflecting unit, configured to receive the collimated beam and reflect the collimated beam to form an incident beam; a detection probe, arranged below a light window of a polishing pad and at least comprising a quartz light tube and a single-core optical fiber, the quartz light tube being configured to receive the incident beam and emit the incident beam from an end, close to a wafer, of the detection probe, and the single-core optical fiber being configured to receive an emergent beam reflected by a surface of the wafer; and a detector, connected to the single-core optical fiber.