A laser apparatus may include: a quantum cascade laser outputting, based on a supplied current, laser light at an oscillation start timing when a first delay time elapses from a current rising timing of the supplied current: an amplifier disposed in a laser light optical path, and selectively amplifying light of a predetermined wavelength to output the amplified laser light to a chamber including a plasma generation region into which a target is fed; and a laser controller controlling a third delay time, from an output timing of a laser output instruction to the current rising timing, to cause a laser light wavelength to be equal to the predetermined wavelength at an aimed timing when a second delay time elapses from the oscillation start timing, based on oscillation parameters including the first delay time, a supplied current waveform, and a device temperature of the quantum cascade laser.

A distributed gain polygon ring laser system includes a substrate ring, top and bottom cover plates, an input pump laser, an output coupler and a number of reflection points. The substrate ring has inner and outer surfaces. The top and bottom cover plates are configured for vacuum sealing with the substrate ring. The input pump laser is configured to direct light into the substrate ring. The plurality of reflection points are spaced around the inner surface of the substrate ring and are configured to reflect light from the input pump laser to the output coupler in a series of reflections.

A laser apparatus may include a beam splitter configured to split a pulse laser beam into a first beam path and a second beam path, an optical sensor provided in the first beam path, an amplifier including an amplification region provided in the second beam path and being configured to amplify and emit the pulse laser beam incident thereon along the second beam path, a wavefront controller provided in the second beam path between the beam splitter and the amplifier, and a processor configured to receive an output signal from the optical sensor and transmit a control signal to the wavefront controller.

A technique which is suitable in joining an end surface of a laser medium to a transparent heat sink for maintaining thermal resistance therebetween low and avoiding large thermal stress from acting on the laser medium is to be provided. An end coat is provided on the end surface of the laser medium, a same-material layer constituted of a same material as the heat sink is provided on a surface of the end coat, a surface of the same-material layer and an end surface of the heat sink are activated in a substantially vacuum environment, and those activated surfaces are bonded in the substantially vacuum environment. A laser apparatus having low thermal resistance between the laser medium and the heat sink and high transparency at a joint interface therebetween, and no large thermal stress acting on the laser medium is thereby obtained.

An optical-resolution photoacoustic microscopy (OR-PAM) system for visualizing water content deep in biological tissue uses an all-fiber 1930-nm hybrid optical parametrically-oscillating emitter. The emitter includes a tunable laser source whose output is amplified by a first erbium-doped fiber amplifier (EDFA). The output of the first amplifier is modulated with a Mach-Zehnder amplitude modulator that receives an RF signal with a nanosecond pulse width and a multiple kilohertz repetition rate. A second EDFA further amplifies the signal and passes it to a fiber circulator that in turn delivers it to a 1950/1550 mm fiber wavelength-division-multiplexing coupler WDM. The coupler introduces the signal to a cavity that includes a spool of highly nonlinear fiber and a Thulium-doped fiber amplifier TDFA. From the TDFA the signal reaches a 50/50 fiber coupler that sends part to a second output TDFA and guides part back to the cavity through a port of the WDM.

A laser apparatus may include, a first frame and a second frame, a sleeve through-hole provided in the second frame, a sleeve insertion hole provided in the first frame, a bolt, a positioning sleeve that is formed in an approximately cylindrical shape into which the bolt can be inserted and that positions the first frame and the second frame by passing through the sleeve through-hole and being inserted into the sleeve insertion hole, a nut that is provided in the first frame and into which the bolt is screwed, and a fall prevention unit that is provided in the second frame and that prevents the bolt and the positioning sleeve from falling.

An optical amplification device includes a first Raman amplifier outputs a first excitation light to a transmission line in a same direction as a signal light, and a second Raman amplifier outputs a second excitation light to the transmission line in an opposite direction to the signal light. The first Raman amplifier includes a first detector detects a first power of a first transmitted light transmitted through a first optical filter. The second Raman amplifier includes a second detector detects second power of a second transmitted light transmitted through a second optical filter. The first Raman amplifier stops output of the first excitation light when the first power is higher than a threshold. The second Raman amplifier stops output of the second excitation light when the second power is reduced from power of the first excitation light transmitted through the second optical filter.

A solid-state laser apparatus may include a first oscillator, a laser light generator, and a plurality of stages of fiber amplifiers. The first oscillator may be configured to output seed light. The laser light generator may be configured to output a pulsed laser light beam generated on a basis of the seed light. The plurality of stages of fiber amplifiers may be disposed in series in an optical path of the pulsed laser light beam, and may include a final stage fiber amplifier. The final stage fiber amplifier may be located in a final stage in the plurality of stages of fiber amplifiers, and may include a silica fiber doped with erbium and ytterbium. A value as a result of division of a cross-sectional area of the silica fiber by a fiber length of the silica fiber may be in a range from 0.7 nm to 1.64 nm both inclusive.

A solid-state laser system may include a first solid-state laser unit, a second solid-state laser unit, a wavelength conversion system, a wavelength detector, and a wavelength controller. The wavelength conversion system may receive a first pulsed laser light beam with a first wavelength and a second pulsed laser light beam with a second wavelength, and output a third pulsed laser light beam with a third wavelength converted from the first and second wavelengths. The wavelength controller may control the first solid-state laser unit to vary the first wavelength on a condition that an absolute value of a difference between a value of a target wavelength and a value of the third wavelength detected by the wavelength detector is equal to or less than a predetermined value, and control the second solid-state laser unit to vary the second wavelength on a condition that the absolute value exceeds the predetermined value.

A laser device may include: a master oscillator including a first laser chamber, a first pair of discharge electrodes provided in the first laser chamber, and an optical resonator, the master oscillator being configured to output a laser beam; a first amplifier including a second laser chamber provided in an optical path of the laser beam outputted from the master oscillator and a second pair of discharge electrodes provided in the second laser chamber at a first gap distance, the first amplifier being configured to amplify the laser beam; and a first beam-adjusting optical system provided in an optical path of the laser beam between the master oscillator and the first amplifier, the first beam-adjusting optical system being configured to adjust the laser beam outputted from the master oscillator such that a beam width of the laser beam entering the first amplifier measured in a direction of electric discharge between the second pair of discharge electrodes is substantially equal to the first gap distance between the second pair of discharge electrodes.