A laser element comprises a substrate; and an n-type semiconductor layer, a light emitting layer, a p-type semiconductor layer, and an electrode layer successively laminated on one principal surface of the substrate, wherein the p-type semiconductor layer includes a ridge raised in a stripe shape, the ridge including a contact layer formed in a layer including a principal surface on a side opposite to the substrate, a stepped portion defined by recessing the contact layer is formed in at least part of a boundary between a lateral surface among surfaces defining outer edges of the ridge, the lateral surface extending along a lengthwise direction of the ridge, and the principal surface of the ridge, and the electrode layer covers the principal surface of the ridge and the stepped portion.

A vertical cavity surface emitting device includes a substrate, a first multilayer film reflecting mirror formed on the substrate, a light-emitting structure layer formed on the first multilayer film reflecting mirror, the light-emitting structure layer including a light-emitting layer; and a second multilayer film reflecting mirror formed on the light-emitting structure layer, the second multilayer film reflecting mirror constituting a resonator between the first multilayer film reflecting mirror and the second multilayer film reflecting mirror. The light-emitting structure layer has a high resistance region and a low resistance region having an electrical resistance lower than an electrical resistance of the high resistance region. The low resistance region has a plurality of partial regions arranged into a ring shape while being separated by the high resistance region in a plane of the light-emitting structure layer.

There is provided a semiconductor laminate, comprising: a substrate; and a p-type layer provided above the substrate and comprising a group III nitride containing Mg, wherein C concentration in the p-type layer is less than 5 × 10.sup.15 cm.sup.-3, O concentration in the p-type layer is less than 5 × 10.sup.15 cm.sup.-3, Si concentration in the p-type layer is less than 1×10.sup.15 cm.sup.-3, and F concentration in the p-type layer is 1×10.sup.14 cm.sup.-3 or more.

An optical device has a gallium and nitrogen containing substrate including a surface region and a strain control region, the strain control region being configured to maintain a quantum well region within a predetermined strain state. The device also has a plurality of quantum well regions overlying the strain control region.

Provided is a nitride semiconductor element that does not cause element breakdown even when driven at high current density. A nitride semiconductor element includes an active layer, an electron block layer formed above the active layer, an AlGaN layer formed on the electron block layer, and a cover layer covering an upper surface of the AlGaN layer and formed of AlGaN or GaN having a lower Al composition ratio than in the AlGaN layer, in which the AlGaN layer includes protrusions provided on a surface opposite to the active layer, and the cover layer covers the protrusions. The AlGaN layer is preferably formed of AlGaN having an Al composition ratio decreasing in a direction away from the active layer, and the protrusions preferably have a frustum shape.

An AlGaInPAs-based semiconductor laser device includes a substrate, an n-type clad layer, an n-type guide layer, an active layer, a p-type guide layer composed of AlGaInP containing Mg as a dopant, a p-type clad layer composed of AlInP containing Mg as a dopant, and a p-type cap layer composed of GaAs. Further, the semiconductor laser device has, between the p-type guide layer and the p-type clad layer, a Mg-atomic concentration peak which suppresses inflow of electrons, moving from the n-type clad layer to the active layer, into the p-type guide layer or the p-type clad layer.

A gallium and nitrogen containing laser diode device. The device has a gallium and nitrogen containing substrate material comprising a surface region. The surface region is configured on either a non-polar crystal orientation or a semi-polar crystal orientation. The device has a recessed region formed within a second region of the substrate material, the second region being between a first region and a third region. The recessed region is configured to block a plurality of defects from migrating from the first region to the third region. The device has an epitaxially formed gallium and nitrogen containing region formed overlying the third region. The epitaxially formed gallium and nitrogen containing region is substantially free from defects migrating from the first region and an active region formed overlying the third region.

Ultraviolet light sources such as UV and DUV laser diodes and light emitting diodes (LEDs) are described. The UV light source may comprise at least one quantum well with first and second photoconductive layers on opposite sides thereof. The UV light source may further comprise at least one optical pump configured to direct pump light to the UV light emitter. The pump light may have a photon energy less than the band gap of the at least one quantum well to increase the conductivity of electrons and holes in the first and second photoconductive layers. The electrons and holes can thereby propagate to the quantum well where at least some of the electrons and holes combine resulting in the emission of UV light.

A method for manufacturing a GaN-based surface-emitting laser by an MOVPE includes: growing a first cladding layer with a {0001} growth plane; growing a guide layer on the first cladding layer; forming holes which are two-dimensionally periodically arranged within the guide layer; etching the guide layer by ICP-RIE using a chlorine-based gas and an argon; supplying a gas containing a nitrogen to cause mass-transport, and then supplying the group-III gas for growth, whereby a first embedding layer closing openings of the holes is formed to form a photonic crystal layer; and growing an active layer and a second cladding layer on the first embedding layer, The step includes a step of referring to already-obtained data on a relationship of an attraction voltage and a ratio of gases in the ICP-RIE with a diameter distribution of air holes embedded, and applying the attraction voltage and the ratio to the ICP-RIE.

A nitride-based semiconductor light-emitting element includes a semiconductor stack body that includes: an N-type first cladding layer; an N-side guide layer; an active layer that includes a well layer and a barrier layer; a P-side guide layer; and a P-type cladding layer. Band gap energy of the P-side guide layer monotonically increases with an increase in distance from the active layer. An average of the band gap energy of the P-side guide layer is greater than or equal to an average of band gap energy of the N-side guide layer. Band gap energy of the barrier layer is less than or equal to a smallest value of the band gap energy of the N-side guide layer and a smallest value of the band gap energy of the P-side guide layer. A thickness of the P-side guide layer is greater than a thickness of the N-side guide layer.