A closely spaced emitter array may include a first emitter comprising a first plurality of structures and a second emitter, adjacent to the first emitter, comprising a second plurality of structures. The first emitter and the second emitter may be configured in the closely spaced emitter array such that different types of structures between the first plurality of structures and the second plurality of structures do not overlap while maintaining close spacing between the first emitter and the second emitter.

A surface-emitting laser includes a substrate; semiconductor layers provided on the substrate, the semiconductor layers including a lower reflector layer, an active layer, and an upper reflector layer, the semiconductor layers forming a mesa; a first insulating film covering the mesa; and a second insulating film covering the first insulating film, wherein the mesa has a polygonal shape in a direction in which the substrate extends, and a vertex of the mesa in the direction in which the substrate extends has a chamfered portion.

A light emitting element (semiconductor laser element) includes a multilayer structure in which a substrate, semiconductor layers to, an insulating layer, and a metal layer are stacked in order. The light emitting element includes a plurality of light emitting portions each of which emits a laser beam. The plurality of light emitting portions each include a ridge (ridge waveguide). The distance from a specific position in an active region in at least one of the light emitting portions to an inner surface of the metal layer is different from that in another of the light emitting portions.

An electrically pumped photonic-crystal surface-emitting laser, the epitaxy structure has a first mesa, the first mesa has multiple air holes and forming a photonic crystal structure, the epitaxy structure further has a second mesa, the second mesa and photonic crystal structure is facing the same direction; a first metal electrode arranged on the insulating layer, and covering the photonic crystal structure; a second metal electrode arranged on the second mesa and protruding out of the groove, making the first metal electrode and the second metal electrode face the same direction; and further make the first metal electrode connect to the first connecting metal and make the second metal electrode connect to the second connecting metal for making the photonic crystal structure become flip chip.

A light emitting element includes a laminated structure 20 in which a first compound semiconductor layer 21, an active layer 23, and a second compound semiconductor layer 22 are laminated, a first light reflecting layer 41, and a second light reflecting layer 42 having a flat shape, a base surface 90 located on a side of a first surface of the first compound semiconductor layer 21 has a first region 91 (upwardly convex first-A region 91A and first-B region 91B) including a protruding portion protruding in a direction away from the active layer and a second region 92 having a flat surface, the first light reflecting layer 41 is formed at least on the first-A region 91A, a second curve formed by the first-B region 91B and a straight line formed by the second region 92 intersects at an angle exceeding 0°, and the second curve includes at least one kind of figure selected from the group consisting of a combination of a downwardly convex curve, a line segment, and an arbitrary curve.

An array type semiconductor laser device includes: a second electrode (p-electrode) disposed on another conductivity type semiconductor layer; a third electrode (n-electrode) disposed on a one conductivity type semiconductor layer and between a first electrode (p-electrode) and the second electrode; a fifth electrode (n-electrode) disposed on the one conductivity type semiconductor layer and between the third electrode and the second electrode; a sixth electrode (n-electrode) disposed on the one conductivity type semiconductor layer and across from the fifth electrode; a first conductor (wire) that electrically connects the second electrode and the third electrode; and a second conductor (n-wiring) that electrically connects the fifth electrode and the sixth electrode.

A VCSEL device includes an N-type metal substrate and laser-emitting units on the N-type metal substrate. Each laser-emitting unit includes an N-type contact layer in contact with the N-type metal substrate; an N-type Bragg reflector layer in contact with the N-type contact layer; a P-type Bragg reflector layer above the N-type Bragg reflector layer; an active emitter layer between the P-type Bragg reflector layer and the N-type Bragg reflector layer; a current restriction layer between the active emitter layer and the P-type Bragg reflector layer; a P-type contact layer in contact with the P-type Bragg reflector layer; and an insulation sidewall surrounding all edges of the N-type and P-type Bragg reflector layers, the N-type and P-type contact layers, the active emitter layer and the current restriction layer. A P-type metal substrate has through holes each aligned with a current restriction hole of a corresponding laser-emitting unit.

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.

A semiconductor device includes: a base including a base surface; a mesa protruding from the base surface in a first direction intersecting the base surface, the mesa including a top surface and two side surfaces on both sides of the top surface, and extending along the base surface; and an electric resistor including a top wall provided on the top surface and a side wall provided on at least one of the two side surfaces, the electric resistor being configured such that a current flows in an extending direction of the mesa.

An optical semiconductor device includes: a base including a base surface; a mesa protruding from the base surface in a first direction intersecting the base surface and extending along the base surface; an optical waveguide layer provided inside the mesa or provided inside the base so as to have a region at least overlapping with the mesa in the first direction; an electric resistance layer including a first region provided on the mesa, and a first extending portion extending from the first region in a direction intersecting an extending direction of the mesa; and a wiring layer including a second region electrically connected to the electric resistance layer and configured to partially cover the first region, and a second extending portion configured to at least partially cover the first extending portion and extending from the second region in a direction intersecting the extending direction of the mesa.