The present disclosure provides a laser pulse sequence energy correction system and method. The correction system includes a fundamental frequency light source, a control unit, an energy adjusting unit and a frequency multiplication crystal; the fundamental frequency light source is configured to output a fundamental frequency pulse laser, and the frequency multiplication crystal is configured to convert the fundamental frequency pulse laser into a multiple frequency pulse laser; the control unit prestores an energy-time curve of the multiple frequency pulse laser, and the control unit is configured to control the energy adjusting unit to adjust the intensity of the fundamental frequency pulse laser incident on the frequency multiplication crystal according to the energy-time curve, so that energy of each pulse in the multiple frequency pulse laser is identical. The technical solution of the present disclosure has advantages of simple structure, reliable device, convenient adjustment and the like.

A seed unit (MO) includes a plurality of optical paths sharing a part thereof and causing light to be resonated thereon, an amplification optical fiber (13) serving as a part of each of the optical paths and amplifying respective light beams resonated on the respective optical paths, and; an AOM (14) arranged at a part shared by the respective optical paths and switchable between a first state, in which the AOM (14) vibrates at a predetermined cycle and emits light incident from the optical paths to the optical paths, and a second state, in which the AOM (14) emits light incident from the optical paths to a path other than the optical paths. A resonance cycle of light having highest power out of the light beams resonated on the optical paths and the predetermined cycle at which the AOM (14) vibrates in the first state have a non-integral multiple relationship.

A seed unit (MO) includes a plurality of optical paths sharing a part thereof and causing light to be resonated thereon, an amplification optical fiber (13) serving as a part of each of the optical paths and amplifying respective light beams resonated on the respective optical paths, and; an AOM (14) arranged at a part shared by the respective optical paths and switchable between a first state, in which the AOM (14) vibrates at a predetermined cycle and emits light incident from the optical paths to the optical paths, and a second state, in which the AOM (14) emits light incident from the optical paths to a path other than the optical paths. A resonance cycle of light having highest power out of the light beams resonated on the optical paths and the predetermined cycle at which the AOM (14) vibrates in the first state have a non-integral multiple relationship.

An infrared detection system comprises the following elements. A laser source provides radiation for illuminating a target (5). This radiation is tuned to at least one wavelength in the fingerprint region of the infrared spectrum. A detector (32) detects radiation backscattered from the target (5). An analyser determines from at least the presence or absence of detected signal in said at least one wavelength whether a predetermined volatile compound is present. An associated detection method is also provided. In embodiments, the laser source is tunable over a plurality of wavelengths, and the detector comprises a hyperspectral imaging system. The laser source may be an optical parametric device has a laser gain medium for generating a pump beam in a pump laser cavity, a pump laser source and a nonlinear medium comprising a ZnGeP.sub.2 (ZGP) crystal. On stimulation by the pump beam, the ZnGeP.sub.2 (ZGP) crystal is adapted to generate a signal beam having a wavelength in a fingerprint region of the spectrum and an idler beam having a wavelength in the mid-infrared region of the spectrum. The laser gain medium and the ZnGeP.sub.2 (ZGP) crystal are located in the pump wave cavity.

An infrared detection system comprises the following elements. A laser source provides radiation for illuminating a target (5). This radiation is tuned to at least one wavelength in the fingerprint region of the infrared spectrum. A detector (32) detects radiation backscattered from the target (5). An analyser determines from at least the presence or absence of detected signal in said at least one wavelength whether a predetermined volatile compound is present. An associated detection method is also provided. In embodiments, the laser source is tunable over a plurality of wavelengths, and the detector comprises a hyperspectral imaging system. The laser source may be an optical parametric device has a laser gain medium for generating a pump beam in a pump laser cavity, a pump laser source and a nonlinear medium comprising a ZnGeP.sub.2 (ZGP) crystal. On stimulation by the pump beam, the ZnGeP.sub.2 (ZGP) crystal is adapted to generate a signal beam having a wavelength in a fingerprint region of the spectrum and an idler beam having a wavelength in the mid-infrared region of the spectrum. The laser gain medium and the ZnGeP.sub.2 (ZGP) crystal are located in the pump wave cavity.

The present disclosure relates to use of a quaternary molybdenum/tungsten tellurite crystal and a device thereof. The quaternary molybdenum/tungsten tellurite crystal is used as an acousto-optic material, wherein the quaternary molybdenum/tungsten tellurite comprises tellurium (Te) and tungsten (W), or tellurium (Te) and molybdenum (Mo). The crystal has abundant kinds, is non-toxic, and includes high, medium and low symmetry crystal systems; it easily produces a large-size and high-quality single crystal and almost meets all requirements of excellent acousto-optic properties. In the present disclosure, by selecting different light transmission directions and excitation source directions to fabricate an acousto-optic device with practical application values according to the requirements of the crystal acousto-optic device and the crystal characteristics, high-performance acousto-optic Q switching laser output is achieved.

The present disclosure relates to tellurite crystals, growing methods of the same, and applications thereof; the crystals a chemical formula of MTe.sub.3O.sub.8, wherein M=Ti, Zr, Hf, which belongs to an Ia-3 space group of a cubic crystal system, wherein a transmittance waveband ranges from visible light to infrared light, with a transparency 70%. According to the present disclosure, a growing method of a tellurite crystal is provided, wherein the crystal may be grown using a flux method, a Czochralski method, or a Bridgman-Stockbarger method. The tellurite crystals may be used as an acousto-optic crystal for fabricating an optical modulation device. The present disclosure takes the lead internationally in growing the tellurite single crystals, the size and quality of which sufficiently meet the demands of practical applications of the tellurite single crystals.

An acousto-optic deflector includes an optical element having a surface with one or more steps formed thereon; a conductive layer formed on the surface with the steps; one or more crystals secured to each step; and electrodes positioned on each surface of each crystal.

An acousto-optic deflector includes an optical element having a surface with one or more steps formed thereon; a conductive layer formed on the surface with the steps; one or more crystals secured to each step; and electrodes positioned on each surface of each crystal.

A Q switch resonator includes: an optical resonator comprising at least two mirrors, and configured to accumulate power of a continuous wave or an intermittent continuous wave incident from an outside; and a switching element provided in the optical resonator. The switching element is configured such that, when the power accumulated in the optical resonator increases to a predetermined level, the switching element outputs an optical pulse by lowering a Q factor from a first level to a second level lower than the first level.