The inventive phase measuring device includes a first A/D converter 2 that digitizes a first periodical input signal X at each predetermined sampling timing and outputs the resultant signal as a digital signal Xd, a first zero-crossing identification means operable to detect a sign of Xd, a counting processing unit 4 that counts a difference in the number of times of zero-crossing detection by the first zero-crossing identification means and calculates the difference at each sampling timing, and a fraction processing unit 5 that computes a fraction of the number of times of zero-crossing detection on the basis of Xd at sampling timings immediately before and immediately after determination of zero-crossing by the first zero-crossing identification means. An averaging processing unit 6 performs averaging by adding up and totalizing the outputs from the counting processing unit 4 and the fraction processing unit 5, thereby computing a phase. The inventive device thus implements a digital phase measuring device and a digital phase difference measuring device that allow input of periodical signals in a wide frequency range and that are capable of accurate and real-time measurement.

According to an aspect, there is provided a spectrometer comprising a first and second enclosed volumes. The second enclosed volume is formed by an absorption cell for containing a sample gas. The first enclosed volume of the spectrometer comprises an interferometer with a source of electromagnetic radiation, a first focusing mirror adapted to focus electromagnetic radiation received from the interferometer to the absorption cell, a second focusing mirror adapted to focus electromagnetic radiation received from the absorption cell and a detector adapted to detect electromagnetic radiation focused by the second focusing mirror. Moreover, the spectrometer comprises a main frame plate on which elements in the first enclosed volume are mounted and which is fixed to the absorption cell arranged on an opposing side of the main frame plate.

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.

A compact and miniaturized Fourier transform photoluminescence (PL) spectrometer is provided comprising five functional modules, which are all mounted on a same baseplate: (i) a sample placement module for positioning and spatially adjusting the sample to be tested, which includes a 3-axis stage (10) and a position mark (11) for the expected front surface of the sample being tested. The stage is employed for positioning the sample directly or a low-temperature optical cryostat that contains the sample (said sample and cryostat being not parts of the spectrometer), the position mark indicates the pre-aligned position for the projection of the sample's front surface in the horizontal plane; (ii) a built-in pump light source module for generating PL signal, which includes two lasers (20) and (21) with different laser wavelengths, the lasers' output can be selected on request in the wavelength range from ultraviolet to near-infrared.

Active FTIR spectroscopy systems and methods for quantitative measurements of concentrations of chemical targets, such as gas, liquid and solid chemical targets, in an open-path measuring arrangement and a method of extracting an effective illumination spectrum of IR light illuminating chemical targets arranged in an open-path measuring arrangement.

An optical device includes: a base that includes a main surface; a movable unit that includes an optical function unit; and an elastic support unit that is connected between the base and the movable unit, and supports the movable unit so that the movable unit is movable along a first direction perpendicular to the main surface. The elastic support unit includes a lever, a first torsion support portion that extends along a second direction perpendicular to the first direction and is connected between the lever and the movable unit, and a second torsion support portion that extends along the second direction and is connected between the lever and the base. A torsional spring constant of the first torsion support portion is greater than a torsional spring constant of the second torsion support portion.

An interferometer arrangement includes a beam splitter (8), two retroreflectors (15, 16), a drive (24) that moves at least one of the retroreflectors to alter an optical path difference between interferometer arms (13, 14), a converging element (18) for reference light, and a reference light detector (19) with at least three detector areas (19a-19d). First and second pairs of detector areas are aligned in respective first and second directions, wherein the first direction, the second direction and a central propagation direction of the reference light at the reference light detector are linearly independent. At least two actuators (9, 10) alter a lateral shear between two reference light partial beams (11, 12), which are reflected back from the interferometer arms and superimposed at the beam splitter, in at least two degrees of freedom. Control electronics (38) control the actuators depending on signals (Sa-Sc) at the detector areas, thereby minimizing the shear.

A microelectromechanical system (MEMS) (10), and a microelectromechanical (MEM) optical interferometer (18), for hyper-spectral imaging and analysis. System (10) includes matrix configured collimating micro lens (16), for receiving and collimating electromagnetic radiation (60) emitted by objects (12) in a scene or sample (14); microelectromechanical optical interferometer (18), for forming divided collimated object emission beam (72) having an optical path difference, and for generating an interference image exiting optical interferometer (18); matrix configured focusing micro lens (20); micro detector (22), for detecting and recording generated interference images; and micro central programming and signal processing unit (24). Applicable for on-line (e.g., real time or near-real time) or off-line hyper-spectral imaging and analyzing, on a miniaturized or ‘micro’ (sub-centimeter [1 cm (10 mm) or less], or sub-millimeter) scale, essentially any types or kinds of biological, physical, or/and chemical, (i.e., biophysicochemical) objects.

A Fourier transform infrared spectrophotometer includes a main interfersometer, a control interferometer, an infrared detector, a control light detector, and a beam splitter block. The beam splitter block is disposed between a beam splitter and the control light detector. The control light detector has an optical axis inclined with respect to an optical axis of a control interference light beam.

In an optical device, an elastic support unit includes a pair of levers which face in a second direction perpendicular to a first direction, a pair of first torsion support portions which are connected between the levers and the base, a pair of second torsion support portions which are connected between the pair of levers and the movable unit, and a first link member that bridges the levers. The levers and the first link member define a light passage opening. Each of connection positions between the levers and the first torsion support portions is located on a side opposite to the movable unit with respect to the center of the light passage opening in a third direction perpendicular to the first direction and the second direction. A maximum width of the light passage opening in the second direction is defined by a gap between the levers in the second direction.