Abstract: A multi-channel light source for use with a wavelength division multiplexed optical communication system includes a modified vertical cavity surface emitting laser (VCSEL) including a gain region and a resonator reflector layer at a first end for coupling with an optical fiber. An optical or electrical pumping source excites a gain region of the laser. An external cavity couples at a second end of the modified VCSEL and has a mirrored end for forming a resonant cavity with the resonator reflector layer permitting the light source to produce a multi-channel optical signal. The modified VCSEL has a cavity length that is substantially extended compared with a conventional VCSEL.

Abstract: A multi-frequency light source is disclosed. In one disclosed aspect, the light source may comprise a gain region defined by a first and second mirror. The gain region may have corresponding resonant modes. An external cavity defined by a third mirror and said second mirror is also provided, with the external cavity having a plurality of resonant modes. The second mirror may be terminated with a layer of high reflectivity. In a further aspect, the second mirror may be terminated with an antiphase layer.

Abstract: A multi-channel light source for use with a wavelength division multiplexed optical communication system includes a modified vertical cavity surface emitting laser (VCSEL) including a gain region and a resonator reflector layer at a first end for coupling with an optical fiber. An optical or electrical pumping source excites a gain region of the laser. An external cavity couples at a second end of the modified VCSEL and has a mirrored end for forming a resonant cavity with the resonator reflector layer permitting the light source to produce a multi-channel optical signal. The modified VCSEL has a cavity length that is substantially extended compared with a conventional VCSEL.

Abstract: Compliant substrates include a compliant single crystal layer formed on an amorphous buffer layer, which is formed on a single crystal base layer. The compliant single crystal layer can be used as a template to support the growth of one or more lattice mismatched layers on the compliant substrate. Various electronic and optoelectronic devices including, for example, photodetectors, long-wavelength semiconductor light-emitting devices, short-wavelength semiconductor light-emitting devices, optical modulators and transistors, can be formed on the compliant substrates. The compliant substrates can be produced by epitaxially forming an intermediate single crystal layer, that can be treated to convert it to an amorphous layer, between two single crystal layers, and treating the intermediate single crystal layer to form an amorphous buffer layer.

Abstract: The polarization instability inherent in laterally-oxidized VCSELs may be mitigated by employing an appropriately-shaped device aperture, a misoriented substrate, one or more cavities or employing the shaped device aperture together with a misoriented substrate and/or cavities. The laterally-oxidized VCSELs are able to operate in a single polarization mode throughout the entire light output power versus intensity curve. Combining the use of misoriented substrates with a device design that has an asymmetric aperture that reinforces the polarization mode favored by the substrate further improves polarization selectivity. Other device designs, however, can also be combined with substrate misorientation to strengthen polarization selectivity.

Abstract: The present invention provides a method for making highly compact vertical cavity surface emitting laser by a lateral oxidation process. Specifically, the present invention allows for the use of well-controlled oxidized regions to bound and to define the aperture of a laser structure in a current controlling oxidation layer, wherein the aperture comprises a conductive region in the oxidation layer. These oxidized regions are formed by the use of a pre-defined bordering pattern of cavities etched in the laser structure, which allow the embedded oxidation layer to be oxidized, and which results in a highly reproducible and manufacturable process.

Abstract: A vertical cavity surface emitting laser (VCSEL) of types otherwise known is provided with integrated electronics. The integrated electronics may be, for example, transistors. Other electronic elements may also be integrally formed with the VCSEL. Also integrally formed with the VCSEL may be a detector for detecting light emitted by the VCSEL. The electronics and/or detector may be of hydrogenated amorphous silicon (a-Si:H). The detector may have transparent contacts, of for example of indium tin oxide (ITO), formed by techniques otherwise known. Improved, on-chip addressing is possible, and improved detector architecture is provided.

Abstract: The present invention provides a highly compact vertical cavity surface emitting laser structure formed by a lateral oxidation process. Specifically, the present invention allows for the use of well-controlled oxidized regions to bound and to define the aperture of a laser structure in a current controlling oxidation layer, wherein the aperture comprises a conductive region in the oxidation layer. These oxidized regions are formed by the use of a pre-defined bounding pattern of cavities etched in the laser structure, which allow the embedded oxidation layer to be oxidized.

Abstract: A solid state laser array is multiplexed using an array of micromirrors to permit high resolution printing in a wide format. Each laser in the laser array and each micromirror in the mirror array is individually controlled. The laser array may be an array of VCSELs produced on a GaAs substrate.

Abstract: The present invention relates to a vertical cavity surface emitting laser device comprising a plurality of semiconductor layers formed upon a substrate and capable of emitting a laser beam of a selected wavelength and a selected polarization, wherein said polarization is established by the presence of stress inducing elements disposed on said free surface of the laser device which induce a stress in the active layers of the laser device. The stress inducing elements are made of a material having a higher coefficient of thermal expansion than the material which comprises the surface layer of the laser device.

Abstract: The present invention provides a highly compact vertical cavity surface emitting laser structure formed by a lateral oxidation process. Specifically, the present invention allows for the use of well-controlled oxidized regions to bound and to define the aperture of a laser structure in a current controlling oxidation layer, wherein the aperture comprises a conductive region in the oxidation layer. These oxidized regions are formed by the use of a pre-defined bounding pattern of cavities etched in the laser structure, which allow the embedded oxidation layer to be oxidized, and which results in a highly reproducible and manufacturable process.

Abstract: A photolithographically patterned spring contact is formed on a substrate and electrically connects contact pads on two devices. The spring contact also compensates for thermal and mechanical variations and other environmental factors. An inherent stress gradient in the spring contact causes a free portion of the spring contact to bend up and away from the substrate. An anchor portion remains fixed to the substrate and is electrically connected to a first contact pad on the substrate. The spring contact is made of an elastic material and the free portion compliantly contacts a second contact pad, thereby electrically interconnecting the two contact pads.

Abstract: A method for fabricating a multiple layer semiconductor device, such as a laser, using impurity-induced, or vacancy-enhanced, intermixing of semiconductor layers to selectively inactivate quantum well regions in the device.

Abstract: An index-guided semiconductor laser diode made by impurity-induced layer disordering (IILD) of GaInP and AlGaInP heterostructures. In some embodiments, prior to the IILD, wing regions flanking an active mesa region are etched down close to the active layer so that the selective IILD involves a shallow diffusion only. High-performance, index-guided (AlGa).sub.0.5 In.sub.0.5 P lasers may be fabricated with this technique, analogous to those made in the AlGaAs material system. Also described are several techniques for reducing parasitic leakage current via the IILD regions, which include methods for providing p-n junctions or high band gap materials to reduce the parasitic leakage. In other embodiments, a planar structure is produced but with an ultra-thin upper cladding layer. Only a shallow IILD step is necessary to penetrate below the active region.

Abstract: Methods for defect-free impurity-induced laser disordering (IILD) of AlGaInP and AlGaAs heterostructures. Phosphorus-doped or As-doped films are used in which silicon serves as a diffusion source and silicon nitride acts as a barrier for selective IILD. High-performance, index-guided (AlGa).sub.0.5 In.sub.0.5 P lasers may be fabricated with this technique, analogous to those made in the AlGaAs material system. The deposition of the diffusion source films preferably is carried out in a low pressure reactor. Also disclosed is a scheme for reducing or eliminating phosphorus overpressure during silicon diffusion into III-V semiconducting material by adding a pre-diffusion anneal step. Defects produced during intermixing are also reduced using a GaInP or GaInP/GaAs cap.

Abstract: The polarity of the semiconductor layers in an AlGaInP semiconductor laser fabricated by impurity induced layer disordering (IILD) is reversed to allow n-doping. Thus, the cladding and confinement layers between the substrate and the active layer will have p-type conductivity. The upper confinement, cladding, and contact layers can be either n or p-type conductivity with n-diffused regions formed by IILD extending down from the contact layer to the lower cladding layer. The electrodes can include either a substrate electrode or a lateral electrode.

Abstract: A fabrication process and several structures for an index-guided laser diode formed by IILD or for a multiple wavelength laser array containing stacked semi-conductive active layers with quantum wells. The laser wavelength is varied laterally by effectively inactivating quantum wells which have transition wavelengths longer than that desired in the selected portion of the device. The quantum wells are inactivated by intermixing them with the surrounding high band gap semiconductor layers. To accomplish this intermixing without affecting the active layer in nearby regions, a finite source of impurity inducing or promoting intermixing is located in proximity to the quantum well to be intermixed, and the sample is annealed under conditions which allow for lateral patterning of the impurity-induced intermixing.

Abstract: Semiconductor lasers with thin tunnel barrier layers inserted between P cladding and P confining/active layers. The tunnel barrier layer creates an energy barrier which reduces the leakage of electrons from the active region, if the laser is a double heterostructure laser, or the confining region, if the laser is a quantum well, either single or multiple, laser into the cladding layer.

Abstract: A method of fabricating monolithic arrays having closely spaced laser stripes which output laser beams with large, but well-controlled, wavelength separations. The method begins by depositing on a substrate a lower cladding layer and a plurality of stacked active regions with different bandgaps and which are separated by etch stop layers. The stacked active regions are stacked in order of decreasing energy bandgaps as one moves away from the substrate. One or more stacks are then formed by etching one or more active layers using a patterned mask and the etch stop layers such that the topmost active region that remains in each stack has a bandgap which corresponds to the desired laser beam color from that stack. An upper cladding layer is then grown over the exposed surfaces. Beneficially, a lateral confinement region is then created around the stacks (such as by using impurity-induced layer disordering).

Abstract: Monolithic arrays having closely spaced laser stripes which output laser beams with large, but well-controlled, wavelength separations. The monolithic array uses a plurality of stacked active regions which are stacked in the order of decreasing energy bandgaps as one moves away from the substrate. Those active regions are separated by one or more thin etch stop layers. Between the bottom active regions and the substrate is a lower cladding layer, while over the topmost active region of each stack is an upper cladding layer. Beneficially, an electrical connection is made to each stack using a heavily doped capping layer/metallic contact above each stack and a metallic contact on the substrate (which is shared by all stacks). Lateral carrier and optical confinement is achieved using a confinement layer which surrounds each stack. Beneficially, that confinement layer is formed using layer induced disordering.