A compound semiconductor has a high electron concentration of 5×10.sup.19 cm.sup.−3 or higher, exhibits an electron mobility of 46 cm.sup.2/V.Math.s or higher, and exhibits a low electric resistance, and thus is usable to produce a high performance semiconductor device. The present invention provides a group 13 nitride semiconductor of n-type conductivity that may be formed as a film on a substrate having a large area size at a temperature of room temperature to 700° C.

A compound semiconductor has a high electron concentration of 5×10.sup.19 cm.sup.−3 or higher, exhibits an electron mobility of 46 cm.sup.2/V.Math.s or higher, and exhibits a low electric resistance, and thus is usable to produce a high performance semiconductor device. The present invention provides a group 13 nitride semiconductor of n-type conductivity that may be formed as a film on a substrate having a large area size at a temperature of room temperature to 700° C.

A semiconductor light-emitting element having a structure in which a substrate, a first reflector, a resonator cavity including an active layer, a second reflector and a transparent conductive film are stacked in this sequence, the semiconductor light-emitting element comprising: a first current constriction portion configured with an oxidation constriction layer; and a second current constriction portion configured with an insulation film, which is formed on an upper face of the second reflector and has an opening, and a contact portion between the transparent conductive film and a semiconductor layer with which the transparent conductive film is in contact, wherein a width d2 of the second current constriction portion is smaller than a width d1 of the first current constriction portion.

A semiconductor light-emitting element having a structure in which a substrate, a first reflector, a resonator cavity including an active layer, a second reflector and a transparent conductive film are stacked in this sequence, the semiconductor light-emitting element comprising: a first current constriction portion configured with an oxidation constriction layer; and a second current constriction portion configured with an insulation film, which is formed on an upper face of the second reflector and has an opening, and a contact portion between the transparent conductive film and a semiconductor layer with which the transparent conductive film is in contact, wherein a width d2 of the second current constriction portion is smaller than a width d1 of the first current constriction portion.

A semiconductor light-emitting element having a structure in which a substrate, a first reflector, a resonator cavity including an active layer, a second reflector and a tunnel junction portion are stacked in this sequence, comprising: a first current constriction portion configured with an oxidation constriction layer; and a second current constriction portion including the tunnel junction portion, wherein a width d2 of the second current constriction portion is smaller than a width d1 of the first current constriction portion.

A light source device in which a plurality of semiconductor light-emitting elements are disposed, each of the plurality of semiconductor light-emitting elements being configured with a first reflector, a resonator cavity including an active layer, and a second reflector which are stacked in this sequence on a semiconductor substrate, wherein in each of the semiconductor light-emitting elements, an electric contact region for supplying carriers to the active layer is disposed on a surface of the second reflector on an opposite side thereof to the active layer, and wherein the plurality of semiconductor light-emitting elements include a first semiconductor light-emitting element of which shape of the contact region is a first shape, and a second semiconductor light-emitting element of which shape of the contact region is a second shape which is different from the first shape.

A light source device in which a plurality of semiconductor light-emitting elements are disposed, each of the plurality of semiconductor light-emitting elements being configured with a first reflector, a resonator cavity including an active layer, and a second reflector which are stacked in this sequence on a semiconductor substrate, wherein in each of the semiconductor light-emitting elements, an electric contact region for supplying carriers to the active layer is disposed on a surface of the second reflector on an opposite side thereof to the active layer, and wherein the plurality of semiconductor light-emitting elements include a first semiconductor light-emitting element of which shape of the contact region is a first shape, and a second semiconductor light-emitting element of which shape of the contact region is a second shape which is different from the first shape.

Disclosed herein are self-mixing interferometry (SMI) sensors, such as may include vertical cavity surface emitting laser (VCSEL) diodes and resonance cavity photodetectors (RCPDs). Structures for the VCSEL diodes and RCPDs are disclosed. In some embodiments, a VCSEL diode and an RCPD are laterally adjacent and formed from a common set of semiconductor layers epitaxially formed on a common substrate. In some embodiments, a first and a second VCSEL diode are laterally adjacent and formed from a common set of semiconductor layers epitaxially formed on a common substrate, and an RCPD is formed on the second VCSEL diode. In some embodiments, a VCSEL diode may include two quantum well layers, with a tunnel junction layer between them. In some embodiments, an RCPD may be vertically integrated with a VCSEL diode.

Disclosed herein are self-mixing interferometry (SMI) sensors, such as may include vertical cavity surface emitting laser (VCSEL) diodes and resonance cavity photodetectors (RCPDs). Structures for the VCSEL diodes and RCPDs are disclosed. In some embodiments, a VCSEL diode and an RCPD are laterally adjacent and formed from a common set of semiconductor layers epitaxially formed on a common substrate. In some embodiments, a first and a second VCSEL diode are laterally adjacent and formed from a common set of semiconductor layers epitaxially formed on a common substrate, and an RCPD is formed on the second VCSEL diode. In some embodiments, a VCSEL diode may include two quantum well layers, with a tunnel junction layer between them. In some embodiments, an RCPD may be vertically integrated with a VCSEL diode.

In one example, a vertical cavity surface emitting laser (VCSEL) may include an active region to produce light at a wavelength, an emission surface to emit the light at the wavelength, a first oxide region spaced apart from the active region by a distance of at least a half-wavelength of the wavelength, a first oxide aperture in the first oxide region, a second oxide region between the first oxide region and the second oxide region, and a second oxide aperture in the second oxide region. The emitted light may have a divergence angle that is based on the respective positions and thicknesses of the first oxide region and the second oxide region.