There is provided a passive Q-switch pulse laser device including a laser medium, and a saturable absorber. The laser medium is disposed between a pair of reflection means included in an optical resonator. The laser medium is excited by specific excitation light to emit emission light. The saturable absorber is disposed on an optical axis of the optical resonator and on a downstream side of the laser medium between the pair of reflection means. The saturable absorber has a transmittance increased by absorption of the emission light. At least one of the pair of reflection means is a polarizing element. The polarizing element has different reflectances with respect to the respective pieces of emission light in polarization directions orthogonal to each other.

There is provided a passive Q-switch pulse laser device including a laser medium, and a saturable absorber. The laser medium is disposed between a pair of reflection means included in an optical resonator. The laser medium is excited by specific excitation light to emit emission light. The saturable absorber is disposed on an optical axis of the optical resonator and on a downstream side of the laser medium between the pair of reflection means. The saturable absorber has a transmittance increased by absorption of the emission light. At least one of the pair of reflection means is a polarizing element. The polarizing element has different reflectances with respect to the respective pieces of emission light in polarization directions orthogonal to each other.

Methods include directing a laser beam to a target along a scan path at a variable scan velocity and adjusting a digital modulation during movement of the laser beam along the scan path and in relation to the variable scan velocity so as to provide a fluence at the target within a predetermined fluence range along the scan path. Some methods include adjusting a width of the laser beam with a zoom beam expander. Apparatus include a laser source situated to emit a laser beam, a 3D scanner situated to receive the laser beam and to direct the laser beam along a scan path in a scanning plane at the target, and a laser source digital modulator coupled to the laser source so as to produce a fluence at the scanning plane along the scan path that is in a predetermined fluence range as the laser beam scan speed changes along the scan path.

Methods include directing a laser beam to a target along a scan path at a variable scan velocity and adjusting a digital modulation during movement of the laser beam along the scan path and in relation to the variable scan velocity so as to provide a fluence at the target within a predetermined fluence range along the scan path. Some methods include adjusting a width of the laser beam with a zoom beam expander. Apparatus include a laser source situated to emit a laser beam, a 3D scanner situated to receive the laser beam and to direct the laser beam along a scan path in a scanning plane at the target, and a laser source digital modulator coupled to the laser source so as to produce a fluence at the scanning plane along the scan path that is in a predetermined fluence range as the laser beam scan speed changes along the scan path.

A laser device is a laser device that includes an output unit that outputs seed light to a light amplifying unit. The output unit has a light source unit that outputs, as the seed light, rays of light with a plurality of wavelengths lying within a gain range of the light amplifying unit, and a seed light control unit that controls an intensity-time waveform of the seed light output from the light source unit.

A quasi-monolithic solid-state laser in which the optical components of the laser cavity are bonded to a common substrate via mounts. The optical components and their mounts are fixedly connected to each other and to the substrate by bonding. While the gain medium is bonded to a mount made of a different material with high thermal conductivity for heat sinking, the cavity's lens and mirror components and their mounts are all made of the same material as the substrate, or a different material that is thermally matched to the substrate, and fixedly mounted on the substrate solely with bonding. The bonding is achieved with adhesive bonding, or some other form of bonding such as molecular bonding, chemically activated direct bonding or hydroxide catalysis bonding.

A planar waveguide amplifier includes a planar waveguide including a flat plate-like core; a first cladding provided on a first principal face of the core; and a second cladding provided on a second principal face of the core, and signal light and pumping light travel into the planar waveguide so that the signal light and the pumping light propagate inside the core in such a manner that optical paths of the signal light and the pumping light overlap each other, and in a zig-zag manner, and the core is an amplification medium containing a rare-earth element serving as an active ion of a three-level system, and absorbs the signal light on the basis of a reduction in intensity of the pumping light.

A laser device is provided that includes an element made of laser-active material and a cladding element bonded to the element so as to allow heat exchange by heat conduction between the cladding element and the element. The laser-active material emitting laser light when excited by pump light. The element being made of a glass. The cladding element being made of a material that exhibits an absorption coefficient for the pump light that is lower than a corresponding absorption coefficient of the glass. The element and cladding element being configured so that the pump light can be directed through the cladding element into the element and/or so that the pump light can be directed through the element into the cladding element.

A photonic-based microwave generator includes a mode-locked laser that generates an optical pulse train, a feedback photodiode that samples the optical pulse train, and a servo amplifier that processes the photodiode output into a servo signal. The servo signal controls the mode-locked laser to suppress relative intensity noise on the optical pulse train. The microwave generator may also include a microwave photodiode for converting the optical pulse train into a microwave signal. The microwave generator may also include a second servo amplifier that processes a low-frequency output of the microwave photodiode into a second servo signal that drives an optical modulator that modulates the optical pulse train. The microwave photodiode, optical modulator, and servo amplifier form a feedback loop that suppresses amplitude noise on the microwave signal. By reducing amplitude noise and relative intensity noise, phase noise caused by amplitude-to-phase noise conversion is minimized.

A light absorbing layer which is bonded to a laser medium to configure a bonded body, wherein the light absorbing layer is formed from a glass material and, in an oscillation wavelength (wavelength of 650 nm or more and less than 1400 nm) of the laser medium, an absorption coefficient is 0.1 to 10.0 cm.sup.-1, a difference in refractive index between the light absorbing layer and the laser medium is within ±0.1, and a difference in linear thermal expansion coefficient between the light absorbing layer and the laser medium is within ±1 ppm/K. The present invention relates to a light absorbing layer for preventing parasitic oscillation, and aims to provide a material capable of suppressing the manufacturing cost and which can be easily processed for preparing a bonded body.