Disclosed is a terahertz, reflection imaging system using a rotating polyhedral mirror and a telecentric f-theta lens. The terahertz reflection imaging system may include a light source configured to output a terahertz, beam, a rotating polyhedral mirror of which a mirror is combined with each of polyhedral faces, and configured to reflect the terahertz beam transmitted from the light source in a direction in which a specimen is disposed, a telecentric f-theta lens configured to transmit the terahertz beam reflected from the rotating polyhedral mirror to the specimen and correct a chief ray of the terahertz beam reflected from the rotating polyhedral mirror to be parallel to an optical axis of the telecentric f-theta lens, and a detector configured to detect a terahertz beam reflected from the specimen.

A method and an apparatus are presented for monitoring a concentration of a specific halogen in a body of water such as a spa or bathing unit for example. The apparatus comprises a housing in which is positioned an optical absorption analyzer for making first and second measurement of transmission of ultraviolet light from a light source emitting light at a specific wavelength. The second and first measurements are taken respectively before and after the ultraviolet light has travelled through a sample of water and are used to derive a concentration of the specific halogen. The derived concentration may then be communicated to a user using a display device and/or may be used to control operational components of a bathing unit for adjusting the concentration of halogen in the water. In some practical implementations, the apparatus may be embodied as a standalone device, which may be configured to float on the water of the bathing unit or, alternatively, may be configured for being installed in-line in a water circulation path of the bathing input by connecting the housing to circulation piping.

The present application relates to a terahertz time-domain spectroscopy system. In this terahertz time-domain spectroscopy system, the femtosecond laser light radiated by the femtosecond laser is collimated by a first diaphragm, and then is split by a beam splitter into a pump light and a probe light. The pump light passes through the first light path module to generate a terahertz pulse, and the probe light passes through the first light path module to generate a linear polarization probe light having the same optical distance as that of the pump light. The linear polarization probe light and the terahertz pulse are combined by a beam combiner to obtain a light beam to be detected carrying the terahertz pulse information. Two electro-optical crystals with the same thickness are used in a detection device simultaneously. Changing the crystal axis angle of the two electro-optical crystals, there is a phase compensation to the two components o light and e light of the probe light, so as to realize linear detection to high power terahertz pulse and improve measurement accuracy.

A thermal infrared sensor for gas measurement including a sensing element. The sensing element includes a thermal detection layer that outputs an electric signal based on a temperature change, a light-receiving surface electrode disposed on a light-receiving surface of the thermal detection layer, and a back electrode disposed on the thermal detection layer opposite the light-receiving surface electrode. The light-receiving surface electrode has a periodic structure configured to selectively absorb infrared light having an absorption wavelength of a sample gas.

A method and an apparatus are presented for monitoring a concentration of a specific halogen in a body of water such as a spa or bathing unit for example. The apparatus comprises a housing in which is positioned an optical absorption analyzer for making first and second measurement of transmission of ultraviolet light from a light source emitting light at a specific wavelength. The second and first measurements are taken respectively before and after the ultraviolet light has travelled through a sample of water and are used to derive a concentration of the specific halogen. The derived concentration may then be communicated to a user using a display device and/or may be used to control operational components of a bathing unit for adjusting the concentration of halogen in the water. In some practical implementations, the apparatus may be embodied as a standalone device, which may be configured to float on the water of the bathing unit or, alternatively, may be configured for being installed in-line in a water circulation path of the bathing input by connecting the housing to circulation piping.

A spectrometer includes a light source that emits a beam into a sample volume comprising an absorbing medium. Thereafter, at least one detector detects at least a portion of the beam emitted by the light source. It is later determined, based on the detected at least a portion of the beam and by a controller, that a position and/or an angle of the beam should be changed. The beam emitted by the light source is then actively steered by an actuation element under control of the controller. In addition, a concentration of the absorbing media can be quantified or otherwise calculated (using the controller or optionally a different processor that can be local or remote). The actuation element(s) can be coupled to one or more of the light source, a detector or detectors, and a reflector or reflectors intermediate the light source and the detector(s).

Disclosed herein are systems and methods related to use of hollow core photonic crystal fibers. A system includes a tube and a collimating lens configured in a first end of the tube, wherein a single mode fiber is coupled to a first end of the collimating lens. A second lens is supported by a structure at a second end of the tube, the second lens receiving a first signal from a second end of the collimating lens and outputting a second signal that is coupled into a first end of a hollow core photonic crystal fiber. A first gas tube is configured to introduce gas through the structure into a chamber and a sealant seals at least one of the collimating lens and the structure within the tube. An output signal is received at a detector that catches the entire beam to suppress multiple-mode beating noise.

A system is provided for analyzing coffee beans. A light sensor senses a level of darkness of a coffee bean and a distance sensor is used to determine a distance between the light sensor and the coffee bean. The sensed level of darkness is then calibrated using the determined distance, thereby to obtain a calibrated (and thereby more accurate) level of darkness. This represents a roasting intensity and is used by a coffee machine to adjust coffee brewing parameters.

A method for automatically detecting, by means of computerized processing, information about temperature evolution and/or about location/distribution of hot spots and/or bands and/or zones on the surface of a brake disc under dynamic operating conditions. The method includes the steps of acquiring a plurality of digital images and/or a digital video, obtaining a representation of each of the digital images and/or digital video frames in the form of matrix data, on which to perform a processing by means of algorithms comprising image analysis or computer vision algorithms, to obtain and provide information about temperature evolution and/or about location/distribution of hot spots and/or bands and/or zones on the zone of interest of the surface of a brake disc.

A spectrophotometer includes: a light source configured to emit light in a wavelength band including an excitation wavelength which causes a photoreaction on a target substance in a sample, the light source emitting a known number of photons of the light having the excitation wavelength; an integrating sphere having a light entrance port through which light emitted from the light source enters and a light emission port provided at a position deviated from an optical axis of the light entering the light entrance port; a sample placement unit provided in the light entrance port; and a light intensity measurement unit configured to measure intensity of light having the excitation wavelength emitted from the light emission port.