Methods for fabricating vertical cavity surface emitting lasers (VCSELs) on a large wafer are provided. An un-patterned epi layer form is bonded onto a first reflector form. The first reflector form includes a first reflector layer and a wafer of a first substrate type. The un-patterned epi layer form includes a plurality of un-patterned layers on a wafer of a second substrate type. The first and second substrate types have different thermal expansion coefficients. A resulting bonded blank is substantially non-varying in a plane that is normal to an intended emission direction of the VCSEL. A first regrowth is performed to form first regrowth layers, some of which are patterned to form a tunnel junction pattern. A second regrowth is performed to form second regrowth layers. A second reflector form is bonded onto the second regrowth layers, wherein the second reflector form includes a second reflector layer.

A chip scale ultra violet laser source includes a plurality of laser elements on a substrate each including a back cavity mirror, a tapered gain medium, an outcoupler, a nonlinear crystal coupled to the outcoupler with a front facet that has a first coating that is anti-reflectivity (AR) to a fundamental wavelength of the laser element and high reflectivity (HR) to ultra violet wavelengths, and has an exit facet that has a second coating that has HR to a fundamental wavelength of the laser element and AR to the ultra violet wavelengths, a photodetector coupled to the outcoupler, a phase modulator coupled to the photodetector and coupled to the back cavity mirror, and a master laser diode on the substrate coupled to the phase modulator of each laser element. Each laser element emits an ultra violet beamlet and is frequency and phase locked to the master laser diode.

A method for forming optical devices. The method includes providing a gallium nitride substrate member having a crystalline surface region and a backside region. The method also includes subjecting the backside region to a laser scribing process to form a plurality of scribe regions on the backside region and forming a metallization material overlying the backside region including the plurality of scribe regions. The method removes at least one optical device using at least one of the scribe regions.

Methods for fabricating vertical cavity surface emitting lasers (VCSELs) on a large wafer are provided. An un-patterned epi layer form is bonded onto a first reflector form. The first reflector form includes a first reflector layer and a wafer of a first substrate type. The un-patterned epi layer form includes a plurality of un-patterned layers on a wafer of a second substrate type. The first and second substrate types have different thermal expansion coefficients. A resulting bonded blank is substantially non-varying in a plane that is normal to an intended emission direction of the VCSEL. A first regrowth is performed to form first regrowth layers, some of which are patterned to form a tunnel junction pattern. A second regrowth is performed to form second regrowth layers. A second reflector form is bonded onto the second regrowth layers, wherein the second reflector form includes a second reflector layer.

The invention relates to an apparatus, system and method for reducing or eliminating polarization effects in a compound semiconductor quantum well optical gain structure including the quantum confined Stark effect (QCSE) and carrier leakage effects. The system comprises a quantum well formed by a monotonic, stepwise and/or continuous compositional grading of a first quantum well interface toward a reduced bandgap, also including a monotonic, stepwise or continuous compositional grading of a second quantum well interface toward an increased bandgap thereby creating a quantum well shape that is substantially symmetric under the influence of electrostatic and/or electrodynamic fields. The system also comprises an electron blocking layer formed by a stepwise or continuous compositional grading starting from the maximum bandgap of the quantum well and increasing toward a larger bandgap, thereby creating a barrier shape with reduced electron sheet charge due to the influence of electrostatic fields.

A vertical-cavity light-emitting element includes: a first reflector; a semiconductor structure layer including a first semiconductor layer, an active layer, a second semiconductor layer, and a third semiconductor layer that are sequentially provided on the first reflector; a transparent electrode on the third semiconductor layer; and a second reflector on the transparent electrode and interposes the structure layer with the first reflector. The third semiconductor layer has a mesa structure to protrude on the second semiconductor layer and be covered by the transparent electrode. The light emitting element further includes a current confining layer including: an insulating film provided in the second semiconductor layer to surround the mesa structure and be in contact with the transparent electrode, the insulating film being an oxide of the second semiconductor layer; and an insulating layer on the insulating film to surround the mesa structure and define a through opening.

A vertical-cavity light-emitting element includes: a first reflector; a semiconductor structure layer including a first semiconductor layer, an active layer, a second semiconductor layer, and a third semiconductor layer that are sequentially provided on the first reflector; a transparent electrode on the third semiconductor layer; and a second reflector on the transparent electrode and interposes the structure layer with the first reflector. The third semiconductor layer has a mesa structure to protrude on the second semiconductor layer and be covered by the transparent electrode. The light emitting element further includes a current confining layer including: an insulating film provided in the second semiconductor layer to surround the mesa structure and be in contact with the transparent electrode, the insulating film being an oxide of the second semiconductor layer; and an insulating layer on the insulating film to surround the mesa structure and define a through opening.

An ultraviolet light emitting element includes a light emitting layer, a cap layer, an electron barrier layer. The light emitting layer has a multi-quantum well structure including barrier layers each including a first AlGaN layer and well layers each including a second AlGaN layer. The electron barrier layer includes at least one first p-type AlGaN layer and at least one second p-type AlGaN layer. The cap layer is located between the first p-type AlGaN layer and one of the well layers closest to the first p-type AlGaN layer. The cap layer is a third AlGaN layer having an Al composition ratio greater than an Al composition ratio of each of the well layers and less than an Al composition ratio of the first p-type AlGaN layer. The cap layer has a thickness of greater than or equal to 1 nm and less than or equal to 7 nm.

An optical modulator is provided, including a lower reflection layer, an active layer formed on the lower reflection layer, and an upper reflection layer formed on the active layer. The active layer includes a multiple quantum well structure including a quantum well layer and a quantum barrier layer. The upper reflection layer includes a dielectric material. A plurality of micro cavity layers are included in the upper reflection layer.

An ultraviolet light emitting element includes a light emitting layer, a cap layer, an electron barrier layer. The light emitting layer has a multi-quantum well structure including barrier layers each including a first AlGaN layer and well layers each including a second AlGaN layer. The electron barrier layer includes at least one first p-type AlGaN layer and at least one second p-type AlGaN layer. The cap layer is located between the first p-type AlGaN layer and one of the well layers closest to the first p-type AlGaN layer. The cap layer is a third AlGaN layer having an Al composition ratio greater than an Al composition ratio of each of the well layers and less than an Al composition ratio of the first p-type AlGaN layer. The cap layer has a thickness of greater than or equal to 1 nm and less than or equal to 7 nm.