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 are a laser element and a method for manufacturing the same, in which the laser element includes a first clad layer, an optical waveguide disposed on the first clad layer, a second clad layer disposed on the optical waveguide, a first electrode disposed on the second clad layer, and a dummy clad disposed on the optical waveguide and apart from the second clad layer and the first electrode.

A system and method for providing laser diodes with broad spectrum is described. GaN-based laser diodes with broad or multi-peaked spectral output operating are obtained in various configurations by having a single laser diode device generating multiple-peak spectral outputs, operate in superluminescene mode, or by use of an RF source and/or a feedback signal. In some other embodiments, multi-peak outputs are achieved by having multiple laser devices output different lasers at different wavelengths.

A semiconductor laser accelerator includes several laser acceleration units linked in a cascade manner, and a controller configured to control excitation current supplied to the laser acceleration units. Each laser acceleration unit includes electrodes, an active layer, a first waveguide layer defining one acceleration channel, a second waveguide layer, and a reflecting layer. One or two optical gratings are formed on one or two sides of the acceleration channel to serve as an accelerating area. The semiconductor laser accelerator exhibits a higher acceleration gradient and a smaller structure while not requiring a complex external optical system. In addition, an optical field is controlled by external excitation current, the matching control of an electron beam and an optical field phase can be realized, and the problem of a phase slip can be solved by means of cascade expansion.

The structures and methods described include an inverted slab-coupled optical waveguide (SCOW) structure, which inverts the polarity of a typical SCOW diode and includes an active region located at an inverted side of the slab section of the inverted SCOW. The inverted SCOWs provide for easily adjustable optical mode confinement or overlap in an active region/gain medium without the risks of generating multiple spatial modes or high electrical resistance associated with traditional non-inverted SCOWs.

An apparatus is configured to operate in a single fundamental transverse mode and the apparatus includes a waveguide layer between an n-doped cladding layer and a p-doped cladding layer. The waveguide layer includes a first waveguide part, and an active layer located between the first waveguide part and the p-doped cladding layer, the active layer being asymmetrically within the waveguide layer closer to the p-doped cladding layer than the n-doped cladding layer. The refractive index of the n-doped cladding layer being equal to or larger than the p-doped cladding layer. A first end of the first waveguide part is adjacent to the n-doped cladding layer. A second end of the first waveguide part is adjacent to a first end of the active layer. A desired donor density is doped in the first waveguide part for controlling the carrier density dependent internal optical loss in the first waveguide part at high injection levels.

An optical device includes a gallium and nitrogen containing substrate comprising a surface region configured in a (20-2-1) orientation, a (30-3-1) orientation, or a (30-31) orientation, within +/−10 degrees toward c-plane and/or a-plane from the orientation. Optical devices having quantum well regions overly the surface region are also disclosed.

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.

A light-emitting device includes a substrate, a laminated structure having a plurality of column portions, and an electrode provided on a side of the laminated structure opposite to the substrate. Each of the plurality of column portions includes a light-emitting layer. The electrode is provided with a plurality of first holes. The plurality of column portions form a first photonic crystal. The electrode forms a second photonic crystal. The first photonic crystal and the second photonic crystal are optically coupled to each other.