Abstract: A method of manufacturing a tuneable laser assembly including a substrate having formed thereon a plurality of tuneable lasers including Multi Quantum Well (MQW) active sections as well as distributed Bragg reflector (DBR) tuning sections. The lasers have respective emission wavelengths and tuning ranges such that the laser assembly can be tuned over a quasi-continuous predetermined wavelength range. The assembly also includes a plurality of passive waveguides coupled to the lasers to receive therefrom the respective emission wavelengths as well as an optical coupler coupled to the waveguides to receive via the waveguides the emissions wavelengths from the lasers. A Multi Quantum Well (MQW) amplifier coupled to the coupler amplifies the emission wavelengths coupled via the optical coupler.

Abstract: A semiconductor laser structure has a laser active region and side trenches extending along the laser active region. At least one heatable stripe, in at least one of the side trenches, is connected to an electric power source. The amount of energy the source supplies to the stripe controls the laser active region temperature to control and offset effects of active region temperature on the emitted wavelength.

Abstract: An optical device having a photonic band gap element operative such that the refractive index can be varied through application of an electrical signal. This enables the manufacture of tuneable lasers, optical add/drop multiplexers and tuneable optical wavelength converters.

Abstract: An optical device comprising a photonic band gap element operative such that the refractive index can be varied through application of an electrical signal. This enables the manufacture of tuneable lasers, optical add/drop multiplexers and tuneable optical wavelength converters.

Abstract: The present invention relates to a semiconductor device with one or more current confinement regions and to a method of manufacturing such a device, particularly buried heterostructure light emitting devices such as semiconductor lasers and light emitting diodes. The device comprises an active layer, a current conduction region, one or more current confinement regions adjacent the current conduction region. The current conduction region and current confinement region are arranged to channel an applied electric current to the active layer. The or each current confinement region includes both a metal-doped current blocking structure and a p-n junction current blocking structure. The p-n current blocking structure is between the current conduction region and the metal-doped current blocking structure.

Abstract: The present invention relates to a semiconductor device (1) with one or more current confinement regions (20,45) and to a method of manufacturing such a device, particularly buried heterostructure light emitting devices such as semiconductor lasers and light emitting diodes. The device (1) comprises an active layer (10), a current conduction region (4), one or more current confinement regions (20,45) adjacent the current conduction region. The current conduction region (4) and current confinement region (20,45) are arranged to channel an applied electric current to the active layer (10). The or each current confinement region includes both a metal-doped current blocking structure (45) and a p-n junction current blocking structure (20). The p-n current blocking structure (20) is between the current conduction region (4) and the metal-doped current blocking structure (45).

Abstract: The present invention relates to a method of etching a semiconductor wafer (100), particularly of a compound semiconductor, in order to facilitate cleaving of devices (200) from the wafer (100) , and to devices (200) cleaved by such a method. A semiconductor device (200) is cleaved from a wafer (100) and comprises a substrate (106) and grown upon the substrate (106) one or more layers (108, 110, 112, 116, 122) , the cleaves (150, 151, 153, 154) thereby defining two pairs of parallel edges (201, 202; 203; 204) of the device (200). Each of the cleaves is guided by a groove (163, 164; 166, 266) etched through the grown layers (108, 110, 112, 116, 122) and partly into the substrate (106).

Abstract: A method of fabricating a semiconductor optical device is provided comprising the steps of depositing planar layers of semiconductor material to form a semiconductor wafer having an optically active region, etching through the optically active region to form a plurality of facets, and simultaneously coating at least one facet and an upper surface of the semiconductor wafer with a coating layer having a thickness and composition such that, during operation of the semiconductor device, the coating layer acts both as a facet coating and as a wafer surface coating. Where the coating layer comprises a dielectric, the layer acts both as an anti-reflection facet coating and as a passivating layer. Where the coating layer comprises a metal, the layer acts both as a high-reflectivity facet coating and as an electrical contacting layer. In a first embodiment the semiconductor device comprises a laser and in a second embodiment comprises a photodetector.