An optoelectronic device grown on a miscut of GaN, wherein the miscut comprises a semi-polar GaN crystal plane (of the GaN) miscut x degrees from an m-plane of the GaN and in a c-direction of the GaN, where −15<x<−1 and 1<x<15 degrees.

The present invention relates to a diode laser with external spectrally selective feedback. It is an object of the invention is to provide an external cavity diode laser with wavelength stabilization which allows an increased overall output power in the desired wavelength range. According to the invention, an external cavity diode laser arrangement is disclosed comprising: an active medium positioned inside an internal laser cavity (10), the internal laser cavity (10) comprising an exit facet (12) adapted for outcoupling laser radiation; an external frequency-selective element (14) positioned outside the internal laser cavity (10) and adapted for wavelength stabilization of the laser radiation; a beam divider (16) positioned outside the internal laser cavity (10) and adapted to divide the outcoupled laser radiation (B0) into a first beam (B1) extending along a first beam path (P1) and a second beam (B2) extending along a second beam path (P2), the first beam (B1) having higher radiant intensity than the second beam (B2) and the first beam path (P1) being different from the second beam path (P2); and an intensity control means to control the radiant intensity incident to the external frequency selective element (14); wherein the external frequency-selective element (14) and the intensity control means are arranged in the second beam path (P2). The intensity control means in the second beam path (P2) may comprise a polarization modifying means (18) and and a polarizer (20) in order to reduce thermal stress at the frequency-selective element (14).

A nitride light emitter includes: a nitride semiconductor light-emitting element including an Al.sub.xGa.sub.1-xN substrate (0≤x≤1) and a multilayer structure above the Al.sub.xGa.sub.1-xN substrate; and a submount substrate on which the nitride semiconductor light-emitting element is mounted. The multilayer structure includes a first clad layer of a first conductivity type, a first light guide layer, a quantum-well active layer, a second light guide layer, and a second clad layer of a second conductivity type which are stacked sequentially from the Al.sub.xGa.sub.1-xN substrate. The multilayer structure and submount substrate are opposed to each other. The submount substrate comprises diamond. The nitride semiconductor light-emitting element has a concave warp on a surface closer to the Al.sub.xGa.sub.1-xN substrate.

A semiconductor laser element includes a semiconductor laminated structure that has a substrate, an n type cladding layer disposed at a front surface side of the substrate, an active layer disposed at an opposite side of the n type cladding layer to the substrate, and p type cladding layers disposed at an opposite side of the active layer to the n type cladding layer. The active layer includes a quantum well layer having a tensile strain for generating TM mode oscillation and the n type cladding layer and the p type cladding layers are respectively constituted of AlGaAs layers.

The present invention relates to a diode laser with external spectrally selective feedback. It is an object of the invention is to provide an external cavity diode laser with wavelength stabilization which allows an increased overall output power in the desired wavelength range. According to the invention, an external cavity diode laser arrangement is disclosed comprising: an active medium positioned inside an internal laser cavity (10), the internal laser cavity (10) comprising an exit facet (12) adapted for outcoupling laser radiation; an external frequency-selective element (14) positioned outside the internal laser cavity (10) and adapted for wavelength stabilization of the laser radiation; a beam divider (16) positioned outside the internal laser cavity (10) and adapted to divide the outcoupled laser radiation (BO) into a first beam (B1) extending along a first beam path (P1) and a second beam (B2) extending along a second beam path (P2), the first beam (B1) having higher radiant intensity than the second beam (B2) and the first beam path (P1) being different from the second beam path (P2); and an intensity control means to control the radiant intensity incident to the external frequency selective element (14); wherein the external frequency-selective element (14) and the intensity control means are arranged in the second beam path (P2). The intensity control means in the second beam path (P2) may comprise a polarization modifying means (18) and a polarizer (20) in order to reduce thermal stress at the frequency-selective element (14).

A design and method for introducing asymmetric crystal strain to control polarization in a tunable VCSEL, either optically or electrically pumped. The invention is especially relevant to wafer- or die-bonded tunable VCSELs. Then, mechanical stress is applied to the half VCSEL device by asymmetric arrangement of metal bond pads.

In an embodiment a radiation-emitting laser diode includes a waveguide layer sequence having an active region configured to generate electromagnetic radiation with a preferred polarization direction, a first waveguide layer of a first doping type and a second waveguide layer of a second doping type, wherein the active region is arranged between the first waveguide layer and the second waveguide layer, wherein refractive indices of the waveguide layer sequence form a first effective refractive index for a transverse electric (TE) mode with its electric field oscillating in a first transverse direction and a second effective refractive index for a transverse magnetic (TM) mode with its electric field oscillating in a second transverse direction, and wherein an effective refractive index difference of the first effective refractive index and the second effective refractive index is at least 4.Math.10.sup.4.

Embodiments provide a light source having a coherent light generator arrangement configured to generate at least one output light, and a waveguide arrangement optically coupled to the coherent light generator arrangement, the waveguide arrangement including at least one first resonator element and at least one second resonator element arranged in different orientations, wherein the waveguide arrangement is configured to interact with the at least one output light to cause the at least one first resonator element and the at least one second resonator element to emit respective first and second optical signals to co-operatively interact with each other to generate an output optical signal, and wherein the light source is configured to change a polarization characteristic of the output optical signal in response to at least one electrical signal applied to the light source to vary at least one of respective magnitudes of the first and second optical signals relative to each other.

A nitride light emitter includes: a nitride semiconductor light-emitting element including an Al.sub.xGa.sub.1-xN substrate (0x1) and a multilayer structure above the Al.sub.xGa.sub.1-xN substrate; and a submount substrate on which the nitride semiconductor light-emitting element is mounted. The multilayer structure includes a first clad layer of a first conductivity type, a first light guide layer, a quantum-well active layer, a second light guide layer, and a second clad layer of a second conductivity type which are stacked sequentially from the Al.sub.xGa.sub.1-xN substrate. The multilayer structure and submount substrate are opposed to each other. The submount substrate comprises diamond. The nitride semiconductor light-emitting element has a concave warp on a surface closer to the Al.sub.xGa.sub.1-xN substrate.

A design and method for introducing asymmetric crystal strain to control polarization in a tunable VCSEL, either optically or electrically pumped. The invention is especially relevant to wafer- or die-bonded tunable VCSELs. Then, mechanical stress is applied to the half VCSEL device by asymmetric arrangement of metal bond pads.