Abstract: A method for making a laser diode with a distributed grating reflector (RT) in a planar section of a semiconductor laser with stabilized wavelength includes providing a diode formed by a substrate (S), a first cladding layer (CL1) arranged on the substrate (S), an active layer (A) arranged on the first cladding layer (CL1) and adapted to emit a radiation, and a second cladding layer (CL2) arranged on the active layer (A), said cladding layers (CL1, CL2) being adapted to form a heterojunction to allow for efficient injection of current into the active layer (A) and optical confinement, and a contact layer. The manufacturing method provides for creating, on a first portion (ZA) of the device, a waveguide (GO) for confinement of the optical radiation and, on the remaining portion (ZP) of the device, two different gratings for light reflection and confinement.

Abstract: A laser-diode device includes a substrate; at least one first cladding layer placed on the substrate; an active layer placed on the first cladding layer and arranged to emit a radiation; at least one second cladding layer placed on the active layer, said cladding layers being adapted to form a heterojunction; a first terminal facet and a second terminal facet placed transversally relative to the cladding layers and to the active layer; a periodic structure, placed in proximity to the second terminal facet and within the second cladding layer, and belonging to an optical cavity, wherein the first terminal facet represents the output mirror from which the radiation generated by the active layer exits, and the second terminal facet, integrated by the periodic structure, represents a second mirror having high reflectivity, so that the radiation produced by the active layer exits almost totally through the first mirror.

Abstract: A method for making a laser diode with a distributed grating reflector (RT) in a planar section of a semiconductor laser with stabilized wavelength includes providing a diode formed by a substrate (S), a first cladding layer (CL1) arranged on the substrate (S), an active layer (A) arranged on the first cladding layer (CL1) and adapted to emit a radiation, and a second cladding layer (CL2) arranged on the active layer (A), said cladding layers (CL1, CL2) being adapted to form a heterojunction to allow for efficient injection of current into the active layer (A) and optical confinement, and a contact layer. The manufacturing method provides for creating, on a first portion (ZA) of the device, a waveguide (GO) for confinement of the optical radiation and, on the remaining portion (ZP) of the device, two different gratings for light reflection and confinement.

Abstract: A laser-diode device includes a substrate; at least one first cladding layer placed on the substrate; an active layer placed on the first cladding layer and arranged to emit a radiation; at least one second cladding layer placed on the active layer, said cladding layers being adapted to form a heterojunction; a first terminal facet and a second terminal facet placed transversally relative to the cladding layers and to the active layer; a periodic structure, placed in proximity to the second terminal facet and within the second cladding layer, and belonging to an optical cavity, wherein the first terminal facet represents the output mirror from which the radiation generated by the active layer exits, and the second terminal facet, integrated by the periodic structure, represents a second mirror having high reflectivity, so that the radiation produced by the active layer exits almost totally through the first mirror.

Abstract: An edge-emitting etched-facet optical semiconductor structure includes a substrate, an active multiple quantum well (MQW) region formed on the substrate, a ridge waveguide formed over the MQW region extending in substantially a longitudinal direction between a waveguide first etched end facet disposed in a first window and a waveguide second etched end facet disposed in a second window, and first and second trenches having non-uniform widths extending in substantially the longitudinal direction between the first and second windows.

Abstract: An N-channel parallel optical transmitter includes a dual-facet continuous-wave laser, two or more optical splitters, and four or more optical modulators. One of the optical splitters has an input coupled to the first facet of the laser, and another has an input coupled to the second facet of the laser. The outputs of the splitters are coupled to the inputs of the optical modulators.

Abstract: An edge-emitting optical semiconductor structure has a substrate, an active multiple quantum well (MQW) region formed on the substrate, and a ridge waveguide extending between first and second etched end facets. The first etched end facet is disposed in a first window, while the second etched end facet is disposed in a second window. The first etched end facet extends between a pair of alcoves in the first window, and the second etched end facet extends between a pair of alcoves in the second window. An integrated device in which two such structures are provided has an H-shaped window where the two structures adjoin each other. The structure can be fabricated using a process that involves a first mask to form the ridge waveguide and then a second mask and an etching process to form the windows.

Abstract: An edge-emitting etched-facet optical semiconductor structure has a substrate, an active multiple quantum well (MQW) region formed on the substrate, and a ridge waveguide formed over the MQW region extending in substantially a longitudinal direction between a waveguide first etched end facet and a waveguide second etched end facet. A mask layer used to form windows in which the etched end facets are disposed consists of a single dielectric material disposed directly on the ridge waveguide. An optical coating consisting of no more than one layer of the same dielectric material of which the second mask is made is disposed directly on the second mask and disposed directly on the windows to coat the etched end facets.

Abstract: A surface-emitting semiconductor laser device is provided that includes an edge-emitting laser formed in various layers of semiconductor material disposed on a semiconductor substrate, a polymer material disposed on the substrate laterally adjacent the layers in which the edge-emitting laser is formed, and a reflector formed in or on an angled side facet of the polymer material generally facing an exit end facet of the laser. Laser light passes out of the exit end facet propagates through the polymer material before being reflected by the reflector out of the device in a direction that is generally normal to the upper surface of the substrate.

Abstract: An EML assembly is provided that has and EAM and a DFB, with the DFB having an asymmetric ¼ wavelength phase shift positioned at a location that is in front of the center of the periodic structure of the DFB. In addition, the EML assembly has a tilted or bent waveguide that reduces reflections occurring at the front end facet, thereby enabling the EAM to produce a relatively high POUT level while also achieving reduced chirp and high single-mode yield in the DFB. By providing the EML assembly with a tilted or bent waveguide, the reflections at the front end facet are reduced without having to use an AR coating on the front end facet that has an extremely low reflectivity. By avoiding the need to use an AR coating on the front end facet that has an extremely low reflectivity, the AR coating that is used on the front end facet can be made using standard sputter deposition techniques to enable higher manufacturing yields to be achieved.

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 tuneable laser assembly includes a substrate having formed thereon a plurality of tuneable lasers, waveguides, an optical coupler and an optical amplifier. The lasers have active sections and distributed Bragg reflector (DBR) tuning sections and are characterised by respective emission wavelengths and tuning ranges such that the laser assembly can be tuned over a quasi-continuous predetermined wavelength range. The DBR tuning sections have a length in the range of about 150-200 um, are of the same optical waveguide of the waveguides, a grating strength (KL) less than about 0,5 and a high reflective (HR) coated back facet enhancing the external quantum efficiency from each said tuning sections. The active sections have a length in the range of about 250-300 um comprised of a high-gain/low-loss multi quantum well (MQW) material. The lasers have a total DBR array length of about 500 um.

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 tuneable laser assembly includes a substrate having formed thereon a plurality of tuneable lasers including 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 waveguides coupled to the lasers to receive therefrom the respective emission wavelengths as well as an optical coupler coupled to the waveguides to receive thereby the emissions wavelengths from the lasers. An optical amplifier is coupled to the optical coupler to amplify the emission wavelengths of the lasers coupled via the optical coupler. The tuning sections of the DBR lasers have a length in the range of about 150-200 um and are of the same optical waveguide of the waveguides routing the emission wavelengths to said optical coupler.

Abstract: A semiconductor laser structure includes a substrate and an active region having at least one active laser layer. The active region is included in a ridge protruding from an exposed surface of the substrate. The ridge extends in the direction of the laser cavity and includes at least two opposed and electrically connected lateral extensions defining respective metal bonding pads distributed along the length of the laser cavity.

Abstract: A semiconductor laser structure includes a substrate and an active region having at least one active laser layer. The active region is included in a ridge protruding from an exposed surface of the substrate. The ridge extends in the direction of the laser cavity and includes at least two opposed and electrically connected lateral extensions defining respective metal bonding pads distributed along the length of the laser cavity.

Abstract: A laser module (1) comprises a Fabry-Perot cavity active element (2) with a facet (3) bearing an anti-reflection coating and an external cavity made by an optical fibre Bragg grating (5) with low reflectivity. This grating (5) presents a non-uniform profile of modulation of the refractive index, asymmetrical in the direction of the grating length, such as to give rise to a position of the equivalent mirror plane that is offset towards the end of the grating (5) that is closer to the active element (2).