A QCL module according to an embodiment includes a package accommodating a QCL element and provided with a window material for extracting a laser beam emitted from the QCL element to the outside, a lens hold member for holding a lens on which the laser beam output from the window material is incident, a cooling fan for cooling the package, and a base for holding the package, the lens hold member, and the cooling fan. The package and the lens hold member are fastened together to the base by a common screw member.

Device, system, and method of aircraft protection and countermeasures against threats. A system for protecting an aircraft against a threat, includes a dual frequency Radio Frequency (RF) module, which includes: a dual-band RF transmitter and a dual-band RF receiver, to transmit and receive high-band RF signals and low-band RF signals; and a threat confirmation and tracking module, to confirm and track a possible incoming threat based on processing of high-band RF signals and low-band RF signals received by the dual-band RF receiver. The system further includes a dual frequency band antenna, to transmit and receive the high-band RF signals and the low-band RF signals. The system also includes a directed high-power laser transmitter, to activate a directed high-power laser beam as countermeasure towards a precise angular position of a confirmed threat.

In one embodiment, an electro-absorption modulator is configured to receive an optical light from an optical light source and outputs a modulated optical signal. The electro-absorption modulator includes a bias voltage that is used to set optimum predetermined modulation performance and an output power of the electro-absorption modulator. A controller is configured to measure a bias current of the optical light source and use a change of the bias current to determine a detuning change that occurs between the electro-absorption modulator and the optical light source. The controller uses the detuning change to automatically control the bias voltage of the electro-absorption modulator to maintain the predetermined modulation performance and maintain the output power of the electro-absorption modulator.

Disclosed is an exchangeable laser unit and an array thereof. The exchangeable laser unit includes cartridge receivers and housings having a uniform shape and uniform optical interfaces. The cartridge receiver adopts the optical interface including a tapered cavity and cylindrical cavity, so that a precise mechanical connection can be achieved between the output of laser of the cartridge receiver and the output of the optical fiber of the housing without professional tools, facilitating standardization of the output components of the laser elements of the cartridge receiver. In addition, the upper-lower guide rails and the upper-lower channels having certain of inclination degree can realize the precise positioning of the cartridge receiver and the housing. When replacing one laser element by a laser element that emits laser with a different wavelength, it is only necessary to replace the cartridge receiver inside the housing. That is, the replacement of laser elements having different wavelengths is converted to the replacement of cartridge receivers, which greatly reduces the difficulty for medical personnel to switch laser wavelengths, and improves the popularization of laser therapeutic instruments in the medical field. In the exchangeable laser array of the disclosure, the cartridge receiver inside the housing can be replaced by other cartridge receiver that emits laser with a different wavelength, and the plurality of housings can be connected with a plurality of wavelength switchers in the back to realize selective output of the wavelength.

An optical refrigeration system that includes a heatlink that is formed by textured crystals that are matched in coefficient of thermal expansion (CTE) to the yttrium lithium fluoride (YLF) cooling crystal, and shaped in geometries that result in very low heat producing losses (HPL). The optical refrigeration system may further include a mirror that is made of a semiconductor-material.

An optical system includes a plurality of lenses and a lens holding member. Each of the plurality of lenses has a cut-off face to have a shape of a partial circle formed by cutting off part of a periphery of a first circle. Cut-off faces of adjacent lenses face each other. The adjacent lenses have an interval between centers of the lenses is smaller than a diameter of the first circle. The lens holding member has an outer surface including a plurality of lens arrangement holes in which the plurality of lenses are respectively disposed. Adjacent lens arrangement holes are linked together to form a linked hole. The linked hole has a shape that represents part of a shape formed by disposing a plurality of second circles, the second circles being partially overlapped, each of the second circles having a diameter larger than a diameter of the first circle.

A method of controlling a laser unit in order to negate heat build-up caused by a laser modulation current, and eliminating artifacts caused by image related thermal effects. Upon receipt of an activation signal, an activation current is applied which causes lasing of the laser unit. Upon receipt of a deactivation signal, the method ceases lasing by selectively applying either an idle current below the activation current, or a cooling current below the idle current.

A laser weapon system is described. Particularly, embodiments describe subsystems of a laser weapon system including those necessary for laser generation, operational control, optical emission, and heat dissipation configured to provide a lightweight unit of reduced dimensions.

A laser device includes a laser oscillator, a dehumidifier, and a controller controlling an operation of the dehumidifier. The controller controls the dehumidifier such that the dew point inside the laser oscillator is lower than the first dew point when a monolayer or less of water molecules is adsorbed, or such that the dew point is equal to or higher than the second dew point when more than a monolayer of water molecules is adsorbed inside the laser oscillator, and is lower than the third dew point at which the dew condensation starts to occur inside the laser oscillator.

The invention relates to a laser system comprising a laser light source (1) that emits laser radiation during operation of the laser system, a modulation means (2) that brings about modulation of the laser radiation emitted by the laser light source (1) such that the spectrum of the laser radiation comprises a carrier (14) and two sidebands (13, 15) that are symmetrically distributed around the carrier, and at least one optical amplifier (5) that amplifies the radiation emitted by the laser light source (1). The invention proposes that an optical filter (4) be provided in the beam path of the laser radiation, upstream of the optical amplifier (5), which filter is intended for removing the spectral portion of the laser radiation at the frequency of one of the two sidebands (13). The laser system is suitable inter alia for generating an artificial guide star (laser guide star) for astronomical telescopes comprising adaptive optics. The invention furthermore relates to a method for generating single-sideband modulated laser radiation.