Provided is a semiconductor laser device including a plurality of semiconductor laser units LDC that are capable of being independently driven, and a spatial light modulator SLM that is optically coupled to a group of the plurality of semiconductor laser units LDC. Each of the semiconductor laser units includes a pair of clad layers having an active layer 4 interposed therebetween, and a diffractive lattice layer 6 that is optically coupled to the active layer 4. The semiconductor laser device includes a ¼ wavelength plate 26 that is disposed between a group of the active layers 4 of the plurality of semiconductor laser units LDC and a reflection film 23, and a polarizing plate 27 that is disposed between the group of the active layers 4 of the plurality of semiconductor laser units LDC and a light emitting surface.

A measurement device includes: an optical gain unit for generating and amplifying light; a transmission optical band variation unit for selecting a specific optical frequency band from the light generated by the optical gain unit, and varying the selected specific optical frequency band to transmit light; a resonant optical frequency variation unit for performing a frequency variation so that multiple resonant optical frequency orders within the specific optical frequency band vary over a variation range narrower than intervals between the respective orders; resonance induction units forming an optical resonance unit which includes the optical gain unit, the transmission optical band variation unit, and the resonant optical frequency variation unit and causes selective oscillation of light having a specific resonant optical frequency within a specific transmission optical band; and a control signal unit for varying each of the transmission optical band variation unit and the resonant optical frequency variation unit.

This semiconductor laser device includes a semiconductor laser chip and a spatial light modulator SLM optically coupled to the semiconductor laser chip. The semiconductor laser chip LDC includes an active layer 4, a pair of cladding layers 2 and 7 sandwiching the active layer 4, a diffraction grating layer 6 optically coupled to the active layer 4, and a drive electrode E3 that is disposed between the cladding layer 2 and the spatial light modulator SLM and supplies an electric current to the active layer 4, and the drive electrode E3 is positioned within an XY plane and has a plurality of openings as viewed from a Z-axis direction and has a non-periodic structure.

A laser device for generating an optical wave including at least two frequencies, such laser device including: a first element including a gain region, a second mirror, distinct from the first element, and arranged so as to form with a first mirror an optical cavity including the gain region; means for pumping the gain region so as to generate the optical wave; means for shaping the light intensity of the optical wave arranged for selecting at least two transverse modes of the optical wave; and means for shaping the longitudinal and/or transversal phase profile of the optical wave and arranged for adjusting at least two transverse modes of the optical wave.

The present invention relates to a method to tune a wavelength of a coherent light signal emitted by a tunable laser, the tunable laser comprising: a cavity, the cavity including: a gain medium, an optical tunable filter, a first and a second mirrors, one of which is partially reflective, wherein the optical tunable filter includes: a first and a second electrodes, a liquid crystal, the method comprising: applying a voltage difference between the first and second electrodes to apply an electric field to the liquid crystal; wherein applying a voltage difference includes: applying the voltage difference for at least a driving time interval lasting less than 1 μs; and varying the voltage difference applied between the first and second electrodes within the driving time interval so that a maximum applied voltage difference is reached and said maximum applied voltage is above 0.1 kV.

There is provided a laser processing device that includes a laser light source configured to output laser light, a spatial light modulator configured to modulate the laser light output from the laser light source according to a phase pattern and emit the modulated laser light, an objective lens configured to converge the laser light emitted from the spatial light modulator onto an object, a controller configured to control a phase pattern to be displayed on the spatial light modulator, and a determiner configured to determine whether operation of the spatial light modulator is normal, in which the controller performs switching control in which the phase pattern to be displayed on the spatial light modulator is switched, and the determiner makes the determination on the basis of a change in intensity of the laser light emitted from the spatial light modulator between before the switching control and after the switching control.

Apparatus for modelocking a fiber laser cavity includes two variable retarder assemblies and a polarizing element. The variable retarder assemblies each have two electronically addressable elements and one fixed element. The first variable retarder assembly prepares a polarization state suitable for NPE modelocking to be launched into the fiber, and the second variable retarder assembly controls the polarization state after exiting the fiber, before being incident on the polarizing element. A control system controls the electronically addressable phase retarders in order to create and modify conditions for modelocking the fiber laser.

Laser systems and methods configured to reconstruct an image of an object from an input comprising: the objects scattered intensity distribution (SID) and the objects compact support; the system comprising: a first lens and a second lens, in a four-focal telescope configuration; a gain with a minor at one end, at first end of the telescope, configured to amplify and reflect a received beam; a reflective spatial light modulator, at second end of the telescope, configured to selectively reflect intensity distributions of a received beam, according to their spatial location, the selective reflection is configured to maintain the intensity distributions of the objects SID; a spatial intensity binary mask, located between the telescope's lenses, comprising an aperture in the form of the objects compact support; the mask is configured to transfer only beams passing through the aperture. The reconstructed objects image is provided at least at the mask's aperture.

Apparatus for modelocking a fiber laser cavity includes two variable retarder assemblies and a polarizing element. The variable retarder assemblies each have two electronically addressable elements and one fixed element. The first variable retarder assembly prepares a polarization state suitable for NPE modelocking to be launched into the fiber, and the second variable retarder assembly controls the polarization state after exiting the fiber, before being incident on the polarizing element. A control system controls the electronically addressable phase retarders in order to create and modify conditions for modelocking the fiber laser.

A method for operating a laser device, including providing a laser pulse in a resonator so that the laser pulse circulates in the resonator, the laser pulse having a carrier wave; determining an offset frequency (f.sub.0) of the frequency comb corresponding to the laser pulse, the frequency comb having a plurality of laser modes (f.sub.m) at a distance (f.sub.rep) from one another, the frequencies of which can be described by the formula: f.sub.m=m*f.sub.rep+f.sub.0, m being a natural number, and varying the offset frequency (f.sub.0) by varying a geometric phase () that is imparted to the carrier wave of the laser pulse per resonator circulation.