A narrow linewidth external cavity semiconductor laser comprises semiconductor optical amplifier chip, comb-shaped optical filter, bandpass optical filter, partial reflection sheet, and collimated light beam coupling output assembly Collimated light beam coupling output assembly is composed of isolator, coupling lens, and output optical fiber. Laser resonant cavity is formed by partial reflection sheet and rear end face of semiconductor optical amplifier chip. Comb-shaped optical filter and bandpass optical filter form single-channel narrowband optical filtering assembly. Bandwidth enables laser to perform single-mode lasing and effectively restrain any other mode lasing. Longitudinal mode's relative position over whole filtering band may be controlled by adjusting laser temperature. Output wavelength and laser power are controlled and in best working state. Etalon is used as comb-shaped optical filter to easily realize narrow linewidth output. Commercial DWDM optical filter is used as bandpass optical filter to improve device wavelength flexibility and reduce costs.

A laser apparatus according to the present invention may comprise: a plurality of reflection mirrors which form a resonance path so as for light to be amplified by an induced emission; a medium having a first surface which forms a vertical surface with respect to the resonance path, and a second interface which does not form a vertical surface with respect to the resonance path, and absorbs energy from a light source and amplifies and emits the light; and a saturable absorber having a second surface which forms a vertical surface with respect to the resonance path, and a second interface which does not form a vertical surface with respect to the resonance path, and generates ultrashort pulses. The laser apparatus according to the present invention has the effects of cutting a saturable absorber having a specific crystallographic axis to thereby make polarization capacity in one direction advantageous and minimize propagation loss. In addition, the laser apparatus according to the present invention has the effect of maximizing transmittivity maintenance capacity of polarization orientation in one direction by arranging a medium and a saturable medium so as to have a specific inclined plane.

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.

An illumination device for generating multiple wavelength, narrow linewidth, single longitudinal and single transversal mode emission, includes a laser-medium inside a laser-resonator configured to receive a pump beam from a single pump diode and produce a laser wave. Laser-resonator ingress and egress mirrors are configured to resonate the laser wave. An an OPO-resonator and OPO crystal are configured to receive the laser wave and produce short and long OPO waves. An OPO-resonator ingress mirror is configured to resonate the short OPO wave with the laser-resonator egress mirror. A nonlinear output crystal is configured to receive the short OPO wave and produce at least one output wave, wherein the the laser-resonator egress mirror is configured to emit at least two of the leaking out laser wave and the output waves.

An illumination device for generating multiple wavelength, narrow linewidth, single longitudinal and single transversal mode emission, includes a laser-medium inside a laser-resonator configured to receive a pump beam from a single pump diode and produce a laser wave. Laser-resonator ingress and egress mirrors are configured to resonate the laser wave. An an OPO-resonator and OPO crystal are configured to receive the laser wave and produce short and long OPO waves. An OPO-resonator ingress mirror is configured to resonate the short OPO wave with the laser-resonator egress mirror. A nonlinear output crystal is configured to receive the short OPO wave and produce at least one output wave, wherein the the laser-resonator egress mirror is configured to emit at least two of the leaking out laser wave and the output waves.

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 dual output semiconductor optical amplifier-based tunable fiber laser is provided that can be switched from low to high power and vice versa. The laser system uses bidirectional semiconductor optical amplifier (SOA) for amplification and hence is able to introduce a unique feature of adjustable dual/single output ports.

A device may include a first photodetector to generate a first current based on an optical power of an optical beam. The device may include a beam splitter to split a portion of the optical beam into a first beam and a second beam. The device may include a wavelength filter to filter the first beam and the second beam. The wavelength filter may filter the second beam differently than the first beam based on a difference between an optical path length of the first beam and an optical path length of the second beam through the wavelength filter. The device may include second and third photodetectors to respectively receive, after the wavelength filter, the first beam and the second beam and to generate respective second currents.

A laser apparatus includes: a laser chamber in which a pair of discharge electrodes is provided; a first beam expander configured to expand a beam width of a beam outputted from the laser chamber at least in a first direction substantially parallel to a direction of electric discharge between the discharge electrodes; and a line narrow optical system including: a second beam expander configured to expand a beam width of the beam outputted from the laser chamber at least in a second direction substantially perpendicular to the first direction, the second beam expander including at least one optical element and a grating configured to perform wavelength dispersion of the beam expanded by the first and second beam expanders, the wavelength dispersion being performed in a plane substantially parallel to the second direction, wherein at least one of the grating and the at least one optical element is arranged so as to compensate for wavelength dispersion caused by the first beam expander.

Disclosed herein is a single pulse laser apparatus which includes a first mirror and a second mirror disposed at both ends of the single pulse laser apparatus and having reflectivities of a predetermined level or more; a gain medium rotated at a predetermined angle and configured to oscillate a laser beam in a manual mode-locking state; a linear polarizer configured to output a beam having a specific polarized component of the oscillated laser beam; an etalon configured to adjust a pulse width of the oscillated laser beam; and an electro-optic modulator configured to perform Q-switching and single pulse switching.