Disclosed is a laser device includes: a rod-shaped laser medium extending in a first direction; a first light source unit including a first base and a plurality of excitation light sources; a second light source unit arranged side by side with the first light source unit in a second direction intersecting with the first direction, the second light source unit including a second base and a plurality of excitation light sources; and a holder supporting the laser medium, the first light source unit, and the second light source unit. At least one of the first base and the holder includes a first regulating part configured to regulate a position of the first base with respect to the holder, and at least one of the second base and the holder includes a second regulating part configured to regulate a position of the second base with respect to the holder.

A system includes a seed laser configured to generate a seed beam and multiple arrays of semiconductor diode lasers configured to generate multiple pump beams. The system also includes a Raman amplifier having a core, a first cladding around the core, and at least a second cladding around the first cladding. The core is configured to amplify the seed beam based on optical pump power provided by the pump beams. Each of the core, the first cladding, and the second cladding includes fused silica, and at least the core and the first cladding are doped. The core has a numerical aperture of approximately 0.06 or less and a diameter of approximately 20 μm to approximately 25 μm. The first cladding has a numerical aperture of approximately 0.17 or less and a diameter of approximately 35 μm to approximately 45 μm.

An optical combiner includes: an optical fiber bundle formed by a plurality of first optical fibers; and a second optical fiber including an end surface joined to an end surface of the optical fiber bundle by fusion-splicing. The plurality of first optical fibers includes a predetermined first optical fiber and other first optical fibers. The predetermined first optical fiber is composed of one or more materials having higher softening temperatures than one or more materials of the other first optical fibers.

A beam quality control device includes an optical fiber, a stress-applying portion, and a temperature controller. The optical fiber has a core and a cladding that surrounds an outer peripheral surface of the core. The stress-applying portion is in surface-contact with at least a portion of an outer peripheral surface of the optical fiber. The stress-applying portion has a coefficient of thermal expansion of the stress-applying portion that is different from a coefficient of thermal expansion of the cladding. The temperature controller controls a temperature of the stress-applying portion. The stress-applying portion contracts or expands due to the temperature being changed by the temperature controller such that a distribution of external force applied by the stress-applying portion to the cladding becomes non-uniform in a peripheral direction of the cladding.

An optical system allows sharing of optical components and seed and pump light to achieve desired optical amplification in laser light while reducing the number of optical components and complexity of the overall optical system and achieving improved performance in lasers and reduced cost in fabrication and final lasers for large scale production of such lasers. Different optical gain sections can be used to allow for sharing of seed and pump light and sharing of optical components while providing multi-stage optical amplification.

In an example, the disclosed technology includes a laser source, comprising a plurality of pump elements configured to generate laser light, a controller coupled to the plurality of pump elements, configured to select individual drive current levels to be provided to respective ones of the plurality of pump elements responsive to a request for a laser power level and at least one power supply coupled to one or more of the plurality of pump elements for driving individual pump elements at selected drive currents.

An object is to respectively provide excitations light from a plurality of light sources to an odd number of fiber pairs. Optical amplifiers are disposed in three fiber pairs including two optical fibers through which optical signals are transmitted, respectively. The optical multiplexer/demultiplexer has inputs connected to light sources and three outputs. An optical multiplexer/demultiplexer has inputs connected to light sources and three outputs. In optical multiplexers/demultiplexers, one input is alternatively connected to any one of the three outputs of the optical multiplexer/demultiplexer, the other input is alternatively connected to any one of the three outputs of the optical multiplexer/demultiplexer, one output is alternatively connected to one optical fiber of any one of the three pairs, and the other output is alternatively connected to the other optical fiber of any one of the three pairs.

A light emitting apparatus includes: a light emitting element configured to emit laser light; a case configured to house the light emitting element, and including a window configured to allow transmittance of the laser light emitted from the light emitting element; a first optical element provided outside the case and configured to converge, in a fast axis direction, the laser light passing through the window; and a second optical element configured to collimate the laser light input via the first optical element, in the fast axis direction, in a state where a beam width in the fast axis direction is narrower than a beam width in the fast axis direction on an incident surface of the first optical element, the second optical element being located closer to the first optical element than a convergence point of the laser light in the fast axis direction by the first optical element.

To limit the number of excitation laser diodes (LDs) in an optical amplification device provided with a redundant excitation LD configuration, the optical amplification device is provided with: an excitation unit which outputs a plurality of excitation lights generated by a plurality of excitation light sources; a first distributing unit of which inputs are connected to the plurality of excitation light sources and which branches input lights and then outputs branched lights as a plurality of first distributed lights; a plurality of second distributing units of which inputs are connected to the first distributing unit and which combines and branches input lights and then outputs branched lights as a plurality of second distributed lights; and a plurality of gain mediums which are respectively excited by the plurality of second distributed lights.

A fiber laser device includes a pumping light source, an amplifying fiber, an input side fiber fusion-spliced on an input side of the amplifying fiber and formed with a HR-FBG, an output side fiber fusion-spliced on an output side of the amplifying fiber and formed with an OC-FBG having a reflectivity smaller than that of the HR-FBG, an output end, and a mode filter, wherein the input side fiber or an intermediate fiber disposed between the amplifying fiber and the input side fiber is fusion-spliced with the amplifying fiber via a fusion splice portion, and at least a portion of the mode filter is disposed in a region between the fusion splice portion and a position separated from the fusion splice portion by a coherence length of beating caused by mode interference of signal light propagating in the amplifying fiber.