A wavelength selection method for a tunable laser includes: obtaining a target wavelength; and calculating target resistance values of two thermistors, respectively, corresponding to the target wavelength. Each of the two thermistors is used to monitor the temperature of a corresponding one of two wavelength selection components. Each of the target resistance values is calculated according to a relationship between a wavelength drift and a resistance change of the corresponding thermistor and according to an initial wavelength and an initial resistance value of the corresponding thermistor corresponding to the initial wavelength. The method further includes: heating the two wavelength selection components to control their temperatures until real-time resistance values of the two thermistors reach the target resistance values, respectively; and stabilizing the real-time resistance values at the target resistance values and outputting a laser beam having the target wavelength.

A wavelength selection method for a tunable laser includes: obtaining a target wavelength; and calculating target resistance values of two thermistors, respectively, corresponding to the target wavelength. Each of the two thermistors is used to monitor the temperature of a corresponding one of two wavelength selection components. Each of the target resistance values is calculated according to a relationship between a wavelength drift and a resistance change of the corresponding thermistor and according to an initial wavelength and an initial resistance value of the corresponding thermistor corresponding to the initial wavelength. The method further includes: heating the two wavelength selection components to control their temperatures until real-time resistance values of the two thermistors reach the target resistance values, respectively; and stabilizing the real-time resistance values at the target resistance values and outputting a laser beam having the target wavelength.

A wavelength sensor for wavelength stabilization of a laser beam includes an etalon placed in the laser beam and tilted with respect to the laser beam. Reflected beams from the etalon form an interference pattern on a segmented photodetector having two detector segments. Output signals from the two detector segments are used to derive an error signal for a closed control loop to effect the wavelength stabilization.

A laser system, comprising: a laser cavity, a gain medium positioned within the laser cavity, a pump source optically coupled to the gain medium, an input minor positioned at a first end of the laser cavity, an output coupler positioned at a second end of the laser cavity, a first etalon positioned within the laser cavity, and a q-switching element positioned within the laser cavity, wherein the laser system is configured to provide a laser beam at a selected wavelength ranging of 1700 to 3000 nm with a tunable spectral range of at least 10 nm. A method for using the laser system e.g., for producing a pulsed laser beam is further disclosed.

A problem with a conventional waveguide type laser device is that in the case in which an isotropic laser medium is used for a core, linearly polarized light is not provided. A ridge waveguide laser device of the present disclosure includes: a substrate; a core joined to the substrate and having a laser medium, the core having a refractive index higher than that of the substrate; and a cladding joined to the core, constituting a ridge waveguide together with the core, and made from a birefringent material having ordinary and extraordinary refractive indices lower than the refractive index of the core, the ordinary and extraordinary refractive indices being different.

A wavelength sensor for wavelength stabilization of a laser beam includes an etalon placed in the laser beam and tilted with respect to the laser beam. Reflected beams from the etalon form an interference pattern on a segmented photodetector having two detector segments. Output signals from the two detector segments are used to derive an error signal for a closed control loop to effect the wavelength stabilization.

In a method, energy is supplied to a first gas discharge chamber of a first stage until a pulsed amplified light beam is output from the first stage and directed toward a second stage. While the energy is supplied to the first gas discharge chamber: a value of an operating parameter of the first gas discharge chamber is measured; it is determined whether to adjust an operating characteristic of the first gas discharge chamber based on the measured value; and, the operating characteristic of the first gas discharge chamber is adjusted if it is determined that the operating characteristic of the first gas discharge chamber should be adjusted. After it is determined that the operating characteristic of the first gas discharge chamber no longer should be adjusted, then an adjustment procedure is applied to an operating characteristic of a second gas discharge chamber of the second stage.

A laser device for laser resonance ionization includes a wavelength variable grating-type titanium-doped sapphire laser and includes a titanium (Ti) doped titanium sapphire crystal disposed within a resonator. The titanium sapphire crystal is fixedly disposed on a stage. The titanium-doped sapphire crystal can be moved in the optical axis direction by the stage, thereby changing the position of the titanium-doped sapphire crystal. The switching between the wideband mode and the high-output mode can be performed by changing the position of the titanium-doped sapphire crystal.

A passively, Q-switched laser operating at an eye safe wavelength of between 1.2 and 1.4 microns is described. The laser may operate at a lasing wavelength of 1.34 microns and use a gain element of Nd:YVO.sub.4 and a saturable absorber element of V:YAG. The position of the resonator axial mode spectrum relative to a gain peak of the gain element is controlled to yield desired characteristics in the laser output.

A passively Q-switched solid-state laser includes a resonator (1) with an active laser material (2) and a decoupling end mirror (6) for decoupling laser pulses that have a pulse duration of less than 1 ns from the resonator (1), an optical fiber (13), into which the laser pulses decoupled from the decoupling end mirror (6) are injected, and a chirped volume Bragg grating (17), at which the laser pulses are reflected after they have passed through the optical fiber (13) for shortening the pulse duration. The pulse duration after the reflection on the chirped volume Bragg grating (17) is less than 30 ps. The active laser material (2) is Nd:YAG and a saturable absorber (3) that is formed from Cr:YAG and has a transmission in the unsaturated state of less than 50% is also arranged in the resonator. The length (a) of the resonator (1) is from 1 mm to 10 mm and the laser pulses decoupled at the decoupling end mirror (6) have a pulse energy from 1 J to 200 J.