Abstract: Disclosed is a laser medium unit that includes a laser medium and a holding body. The laser medium has a pair of end surfaces. The holding body surrounds the laser medium when viewed form a direction intersecting with the pair of end surfaces and holds the laser medium. The holding body includes a deformation allowing portion that extends from the inside to the outside of the holding body when viewed from the direction intersecting with the pair of end surfaces. The laser medium and the holding body are in contact with each other. A contact region of the holding body with the laser medium has a width in the direction intersecting with the pair of end surfaces and extends along a side surface of the laser medium when viewed from the direction intersecting with the pair of end surfaces.

Abstract: A laser device includes a vacuum container including a wall portion, a laser medium disposed inside the vacuum container, a cooler disposed outside the vacuum container, and a heat conductor penetrating the wall portion in a predetermined direction and connected to the laser medium and the cooler.

Abstract: An optical amplification device includes: a laser medium that amplifies input light to generate output light; an excitation light source that supplies excitation light used for amplifying the input light, to the laser medium; a resonator that includes a pair of first optical elements and disposed to optically face each other with the laser medium interposed between the first optical elements and that resonates generated light generated in the laser medium through the supply of the excitation light; and an optical switch disposed on an optical path of the resonator between the pair of first optical elements.

Abstract: A laser device includes a first laser medium and a second laser medium that have a first surface and a second surface opposite to the first surface, and receive input of excitation light and seed light from the first surface side to amplify the seed light, a holder that holds the first laser medium and the second laser medium; and a pair of cooling units that cool the first laser medium and the second laser medium according to change in volume of a refrigerant.

Abstract: A laser device includes a first laser medium and a second laser medium that have a first surface and a second surface opposite to the first surface, and receive input of excitation light and seed light from the first surface side to amplify the seed light, a holder that holds the first laser medium and the second laser medium; and a pair of cooling units that cool the first laser medium and the second laser medium according to change in volume of a refrigerant.

Abstract: Provided is a laser device including N semiconductor laser array stacks, a prismatic optical system that shifts optical axes of luminous fluxes respectively output from the N semiconductor laser array stacks so as to decrease intervals among the luminous fluxes, and an imaging optical system that causes the luminous fluxes to be condensed and deflected for each luminous flux. The imaging optical system causes the luminous fluxes to be deflected so that the luminous fluxes overlap each other at a predetermined position and generates a light-condensing point of the luminous fluxes between the imaging optical system and the predetermined position.

Abstract: Provided is a laser device including N semiconductor laser array stacks, a prismatic optical system that shifts optical axes of luminous fluxes respectively output from the N semiconductor laser array stacks so as to decrease intervals among the luminous fluxes, and an imaging optical system that causes the luminous fluxes to be condensed and deflected for each luminous flux. The imaging optical system causes the luminous fluxes to be deflected so that the luminous fluxes overlap each other at a predetermined position and generates a light-condensing point of the luminous fluxes between the imaging optical system and the predetermined position.