Abstract: A measuring and calculating apparatus to measure and calculate a positional displacement amount of a pattern on a surface of a target object. The apparatus includes: a measuring unit to measure a first two-dimensional intensity distribution of a first diffracted light and a second two-dimensional intensity distribution of a second diffracted light; a storage unit to store a first and a second measurement data respectively indicating the first and the second two-dimensional intensity distribution; and an arithmetic unit to execute arithmetic processing using the first and the second measurement data to acquire difference data between the first and the second measurement data, and calculate a positional displacement amount of a difference pattern between the first and second patterns in accordance with the difference data.

Abstract: Various implementations of visual inspector attachments for fiber connector cleaners are disclosed. The example fiber optic inspection module includes a camera to capture an image of an end-face, a light source to illuminate the end-face, and a first mirror that reflects light from the light source to the end-face and includes a fixed point that allows the first mirror to pivot. Alternatively, an example fiber optic inspection module includes a camera to capture an image of an end-face, a light source to illuminate the end-face, and a first mirror that reflects light from the light source to the end-face and the first mirror moves in an upward direction.

Abstract: A first optical system (10) according to the present disclosure includes a first lens (111) that guides light (LO) to a diffraction grating (3), a second lens (112) that collimates first diffracted light (L1) that was focused at a first focal point (f1), a pair of first mirrors (12, 13), a third lens (113) that focuses the first diffracted light (L1) at a second focal point (f2), and a fourth lens (114) that guides the first diffracted light (L1) that was focused by the third lens (113) to the diffraction grating (3). The first lens (111) and the fourth lens (114) have a substantially identical first focal length. The second lens (112) and the third lens (113) have a substantially identical second focal length. A first distance along an optical path from the first focal point (f1) to the second focal point (f2) is determined by a first predetermined condition.

Abstract: A light detection device includes: a first support part disposed on a mounting surface of the wiring board; a Fabry-Perot interference filter disposed in a first support region of the first support part; and a temperature detector, wherein the temperature detector is disposed on the mounting surface such that at least a part of the temperature detector overlaps a part of the Fabry-Perot interference filter when seen in a first direction perpendicular to the mounting surface and such that at least a part of the temperature detector overlaps a part of the first support part when seen in a second direction in which the first support part and the light detector are aligned with each other, and wherein a first distance between the temperature detector and the first support part in the second direction is smaller than a first width of the first support region in the second direction.

Abstract: A system includes first and second radiation sources, first and second detectors, a signal digitizer, a controller, and an analyzer. The first and second radiation sources generate respective first and second beams of radiation to irradiate a target. The first beam and second beams each include a first wavelength operated at a first modulation frequency and a second wavelength operated at a second modulation frequency. The first and second detectors each include a photo-sensitive element that generate first or second detection signals, a Faraday shielding enclosure, a signal amplifier, and a frequency mixer to frequency-adjust the first or second detection signals. The controller provides timing information to inform an activation scheme of the first and second radiation sources and corresponding radiation detection events at the first and second detectors. The analyzer analyzes the first and second detection signals and determines at least amplitude and phase information of the scattered radiation.

Abstract: A differential interference imaging system capable of rapidly changing shear direction and amount includes: a light source (101), a filter (102), a polarizer (103), a sample stage (104), an infinite imaging microobjective (105), a tube lens (106), a shear component, an analyzer (113), and an image sensor (114). After the light intensity and a polarization direction is adjusted, the linearly polarized light passes through a transparent sample, to be collected by the infinite imaging microobjective (105) and to implement imaging through the tube lens (106). An imaging beam is divided into two linearly polarized light fields which are perpendicular to each other in the polarization directions and have tiny shear amount, then they are further combined into an interference light filed by the analyzer (103) to form a differential interference image in the image sensor (114). The system may be flexibly assembled, is simple in structure and easy to implement.

Abstract: A silicon Fourier transform spectrometer and an optical spectrum reconstruction method are disclosed. The spectrometer includes a waveguide input coupler, cascaded optical switches, unbalanced subwavelength grating (SWG) waveguide pairs, and a germanium silicon detector, where the cascaded optical switches are connected through unbalanced SWG waveguide pairs. The state of the optical switches are adjusted to digitally configure the optical path, so as to constitute a series of unbalanced Mach-Zehnder interferometer (MZI) arrays with different optical path differences, to realize a Fourier transform spectrometer based on spatial heterodyne. The optical spectrum is reconstructed by using a compressed sensing algorithm.