An optical semiconductor device outputting a predetermined wavelength of laser light includes a quantum well active layer positioned between a p-type cladding layer and an n-type cladding layer in thickness direction. The optical semiconductor device includes a separate confinement heterostructure layer positioned between the quantum well active layer and the n-type cladding layer. The optical semiconductor device further includes an electric-field-distribution-control layer positioned between the separate confinement heterostructure layer and the n-type cladding layer and configured by at least two semiconductor layers having band gap energy greater than band gap energy of a barrier layer constituting the quantum well active layer. The quantum well active layer is doped with 0.3 to 1×10.sup.18/cm.sup.3 of n-type impurity.

An example apparatus may include a first plate having a first side. A first plurality of fins may be integral with the first side of the first plate and protruding perpendicularly therefrom. The first plurality of fins may be arranged in first concentric circles separated radially by a first distance. The apparatus may also include a second plate having a first side. The second plate may be rotatably coupled to the first plate. A second plurality of fins may be integral with the first side of the second plate and protruding perpendicularly therefrom. The second plurality of fins may be arranged in second concentric circles separated radially by the first distance. Each fin of the second plurality of fins may interpose between adjacent fins of the first plurality of fins to transfer heat between the second plate and the first plate.

A laser apparatus that can generate a high-quality laser beam is provided. The laser apparatus is provided with a laser medium and an insulation layer. The laser medium has a first surface and a second surface. Incident laser light is incident on the first surface. The second surface totally reflects the incident laser light that is incident to the second surface at an incident angle equal to or larger than a critical angle. The insulation layer covers a second area of the second surface that surrounds a first area of the second surface, the first area totally reflecting the incident laser light. The laser medium is exposed in the first area.

A supporting member supports a peeled end portion formed at an end portion in longitudinal direction representing first direction of an optical fiber, the optical fiber including: a core wire including a core and a cladding; and a jacket configured to enclose the core wire, the jacket being removed at the peeled end portion to expose the core wire. The supporting member includes: a first member; a second member fixed to the first member; a housing portion provided between the first member and the second member, the housing portion extending along the peeled end portion and being configured to house the peeled end portion; and a processed member housed in the housing portion and provided around the peeled end portion, the processed member being configured to cause transmission or scattering of light leaking from the peeled end portion.

A supporting member supports a peeled end portion formed at an end portion in longitudinal direction representing first direction of an optical fiber, the optical fiber including: a core wire including a core and a cladding; and a jacket configured to enclose the core wire, the jacket being removed at the peeled end portion to expose the core wire. The supporting member includes: a first member; a second member fixed to the first member; a housing portion provided between the first member and the second member, the housing portion extending along the peeled end portion and being configured to house the peeled end portion; and a processed member housed in the housing portion and provided around the peeled end portion, the processed member being configured to cause transmission or scattering of light leaking from the peeled end portion.

An actively cooled end-pumped solid-state laser gain device includes a bulk solid-state gain medium. An input-end of the gain medium receives a pump laser beam incident thereon and propagating in the direction toward an opposite output-end. The metal foil is disposed over a face of the gain medium extending between the input- and output-ends. A housing cooperates with the metal foil to form a coolant channel on the face the gain medium. The coolant channel has an inlet and an outlet configured to conduct a flow of coolant along the metal foil from the input-end towards the output-end. The metal foil is secured between the gain medium and portions of the housing running adjacent to the coolant channel. The metal foil provides a reliable thermal contact and imparts little or no stress on the bulk gain medium.

A testing device may include a stage associated with holding an emitter wafer during testing of an emitter. The stage may be arranged such that light emitted by the emitter passes through the stage. The testing device may include a heat sink arranged such that the light emitted by the emitter during the testing is emitted in a direction away from the heat sink, and such that a first surface of the heat sink is near a surface of the emitter wafer during the testing but does not contact the surface of the emitter wafer. The testing device may include a probe card, associated with performing the testing of the emitter, that is arranged over a second surface of the heat sink such that, during the testing of the emitter, a probe of the probe card contacts a probe pad for the emitter through an opening in the heat sink.

A testing device may include a stage associated with holding an emitter wafer during testing of an emitter. The stage may be arranged such that light emitted by the emitter passes through the stage. The testing device may include a heat sink arranged such that the light emitted by the emitter during the testing is emitted in a direction away from the heat sink, and such that a first surface of the heat sink is near a surface of the emitter wafer during the testing but does not contact the surface of the emitter wafer. The testing device may include a probe card, associated with performing the testing of the emitter, that is arranged over a second surface of the heat sink such that, during the testing of the emitter, a probe of the probe card contacts a probe pad for the emitter through an opening in the heat sink.

In various embodiments, laser systems or resonators incorporate two separate cooling loops that may be operated at different cooling temperatures. One cooling loop, which may be operated at a lower temperature, cools beam emitters. The other cooling loop, which may be operated at a higher temperature, cools other mechanical and/or optical components, for example optical elements such as lenses and/or reflectors.

There are provided high power laser systems for performing decommissioning of structures in land based boreholes, and wells, offshore, and other remote and hazardous locations, and using those system to perform decommissioning operations. In particular embodiments the laser system is a Class I system and reduces emission of materials created during laser cutting operations. The laser systems can include lifting and removal equipment for removing laser sectioned material.