The disclosure provides a high-frequency-reproducibility laser frequency stabilization method and device based on multi-point acquisition of laser tube temperature. The laser frequency stabilization device includes: a frequency stabilization control circuit. The frequency stabilization control circuit includes a polarizing beam splitter, an optical power conversion circuit, an A/D conversion circuit, a temperature measuring circuit, a microprocessor, a D/A converter and a heating film driver. The polarizing beam splitter is disposed outside any one of laser transmitting holes. The optical power conversion circuit is disposed on reflection and refraction optical paths of the polarizing beam splitter. The optical power conversion circuit, the A/D conversion circuit, the microprocessor, the D/A converter, the heating film driver and a plurality of groups of heating films are sequentially in one-way connection. Temperature sensors, the temperature measuring circuit and the microprocessor are sequentially in one-way connection.

A laser apparatus according to the present disclosure includes an excitation light source configured to output excitation light, a laser crystal disposed on an optical path of the excitation light, a first monitor device disposed on an optical path of transmitted excitation light after having transmitted through the laser crystal to monitor the transmitted excitation light, a temperature adjustment device configured to adjust a temperature of the excitation light source to a constant temperature based on a temperature command value, and a controller configured to change the temperature command value based on a result of monitoring by the first monitor device.

A single-frequency laser apparatus comprises a mirror and a volume Bragg grating (VBG) reflector defining a laser cavity therebetween and an optical gain material for emitting and amplifying an intra-cavity beam in the laser cavity. The optical gain material comprises a transition-metal doped crystal such as a crystal doped with transition-metal ions selected from one or more of Ti.sup.3+ ions, Cr.sup.2+ ions, Cr.sup.3+ ions or Cr.sup.4+ ions. A reflectivity spectrum of the VBG reflector and an optical length of the laser cavity are selected so that a beam output from the laser cavity is a single-frequency output beam and/or includes only one longitudinal mode of the laser cavity. The laser apparatus may provide a robust, compact, low cost, high-power wavelength adjustable (from approximately 650 to 950 nm), narrow linewidth (<100 kHz), single frequency laser source which is suitable for a wide range of applications from laser sensing, spectroscopy, and high precision frequency metrology sectors.

Provided are a time and frequency control method and system for optical comb. The method includes: controlling an optical comb measuring system to start and to generate an optical comb; obtaining monitoring data, wherein the monitoring data comprises a working temperature, a mode-locked frequency and a light pump power, wherein the mode-locked frequency comprises a repetition frequency and a carrier envelope phase locked at the end of starting the optical comb measuring system; determining whether an offset of the mode-locked frequency exceeds a self-feedback adjustment range of a hardware adjustment circuit; and in response to any of the repetition frequency and the carrier envelope phase exceeds the self-feedback adjustment range, adjusting the working temperature and the light pump power until the mode-locked frequency returns back into the self-feedback adjustment range.

An apparatus and method for calculating the frequency of the light.

A current control device supplies a current to a semiconductor laser in order to output laser light to the semiconductor laser, and includes a current commander and a supplier. The current commander outputs a command value corresponding to a current value by increasing the command value with a lapse of time until reaching a target command value corresponding to a current value for outputting the laser light with a predetermined strength. The supplier supplies a current with a size corresponding to the command value output by the current commander to the semiconductor laser.

A laser adjustment method includes a first adjustment step and a second adjustment step. In the first adjustment step, using a light detector detecting a second harmonic light, optical intensity and wavelength of the second harmonic light is detected and a first temperature adjuster is adjusted to adjust temperatures of a Nd:YVO.sub.4 crystal and a KTP crystal such that the detected wavelength of the second harmonic light approaches a desired wavelength and such that the optical intensity of the second harmonic light reaches at least a predetermined value. In the second adjustment step, after the first adjustment step, a temperature of an etalon is adjusted by a second temperature adjuster such that the detected wavelength of the second harmonic light approaches the desired wavelength and such that the optical intensity of the second harmonic light reaches at least a predetermined value.

A thermo-electric cooling (TEC) system is presented for cooling of a device, such a laser for example. The TECT system comprises first and second heat pumping assemblies, and a control unit associated at least with said second heat pumping assembly. Each heat pumping assembly has a heat source from which heat is pumped and a heat drain through which pumped heat is dissipated. The at least first and second heat pumping assemblies are arranged in a cascade relationship having at least one thermal interface between the heat source of the second heat pumping assembly and the heat drain of the first heat pumping assembly, the heat source of the first heat pumping assembly being thermally coupled to the electronic device which is to be cooled by evacuating heat therefrom. The control unit is configured and operable to carry out at least one of the following: (i) operating said second heat pumping assembly to provide a desired temperature condition such that temperature of the heat drain of said first heat pumping assembly is either desirably low or by a certain value lower than temperature of the heat source of said first heat pumping assembly; and (ii) operating said second heat pumping assembly to maintain predetermined temperature of said thermal interface.

A calculation part calculates a maximum temperature reached which is reached by the coolant or component of each part, in the case of machining in accordance with laser machining conditions that were inputted or set, based on the cooling capacity of a chiller, tank volume of the chiller, heat generation amount from the laser oscillator, heat capacity of a cooled part of the laser device, etc. which are recorded in a recording part, and the temperature of each part measured by temperature detection parts, etc. In the case that the maximum temperature reached would exceed the allowed maximum temperature, a warning is made prior to starting laser machining.

A laser oscillation cooling device (100) is provided with a light emitting section (1) that emits laser excitation light (Z1), a laser excitation section (2) that excites the laser excitation light (Z1) to emit laser light (Z2) and locally generates heat, a storage tank (3) capable of storing an extremely low temperature liquid (L), a pressurizing section (31) that brings extremely low temperature liquid (L) into a sub-cool state by pressurizing the inside of the storage tank (3), and a jetting supply section (4) that removes heat from the laser excitation section (2) by jetting the extremely low temperature liquid (L) in the sub-cool state to the laser excitation section (2).