Abstract: A semiconductor laser including: an optical resonator that has a first compound semiconductor layer containing an n-type impurity, a second compound semiconductor layer containing a p-type impurity, and a light-emitting layer provided between the first compound semiconductor layer and the second compound semiconductor layer; and a pulse injection means that injects excitation energy for a sub-nanosecond duration into the optical resonator, wherein the optical resonator has a multi-section structure separated into at least one gain region and at least one absorption region, and the semiconductor laser generates optical pulses having a pulse width shorter than 2.5 times the photon lifetime in the optical resonator.

Abstract: A semiconductor laser including: an optical resonator that has a first compound semiconductor layer containing an n-type impurity, a second compound semiconductor layer containing a p-type impurity, and a light-emitting layer provided between the first compound semiconductor layer and the second compound semiconductor layer; and a pulse injection means that injects excitation energy for a sub-nanosecond duration into the optical resonator, wherein the light-emitting layer has an at least five-period multiple quantum well structure, and the semiconductor laser generates optical pulses having a pulse width shorter than 2.5 times the photon lifetime in the optical resonator.

Abstract: A light-emitting element, in which a light whose emission angle distribution is one of Lambert's emission law or uniform Isotropic emission, is extracted from a light extraction opening window, and an in-plane distribution of a light intensity on a light extraction surface of the light extraction opening window is uniform, and which can be used as a reference light source when measuring an absolute light quantity of a weak light emitted from a luminous body which is a measurement object.

Abstract: A light-emitting element, in which a light whose emission angle distribution is one of Lambert's emission law or uniform Isotropic emission, is extracted from a light extraction opening window, and an in-plane distribution of a light intensity on a light extraction surface of the light extraction opening window is uniform, and which can be used as a reference light source when measuring an absolute light quantity of a weak light emitted from a luminous body which is a measurement object.

Abstract: A method includes epitaxially growing a semiconductor layer with a free surface and performing an anneal that reduces atomic roughness on the free surface. The free surface has an orientation with respect to lattice axes of the layer for which atoms in flat regions of the free surface have more chemical bonds to the layer than do, at least, some of the atoms at edges of monolayer steps on the free surface.

Abstract: A method includes epitaxially growing a semiconductor layer with a free surface and performing an anneal that reduces atomic roughness on the free surface. The free surface has an orientation with respect to lattice axes of the layer for which atoms in flat regions of the free surface have more chemical bonds to the layer than do, at least, some of the atoms at edges of monolayer steps on the free surface.

Abstract: A method includes epitaxially growing a semiconductor layer with a free surface and performing an anneal that reduces atomic roughness on the free surface. The free surface has an orientation with respect to lattice axes of the layer for which atoms in flat regions of the free surface have more chemical bonds to the layer than do, at least, some of the atoms at edges of monolayer steps on the free surface.