Abstract: Data rate that can be supported by a photodetector can be limited by the aperture size of the photodetector. In some embodiments, the minimum aperture diameter can be about 30 um. This limitation is due, for example, to an inability of the optics to focus the beam to a smaller spot, and the mechanical tolerances of the assembly process. The techniques described in the present disclosure can reduce the optical spot size and improve on the mechanical tolerances that are achievable, thereby improving the photodetector and VCSEL manufacturing processes and systems. A photodetector or VCSEL system design with higher data rate and lower production cost can be achieved using the techniques described herein.

Abstract: A three-terminal VCSEL is provided that has a reduced fall time that allows the VCSEL to be operated at higher speeds. Methods of operating the three-terminal VCSEL are also provided. The VCSEL can be operated at higher speeds without decreasing the optical output of the VCSEL when its in the logical HIGH state.

Abstract: A three-terminal VCSEL is provided that has a reduced fall time that allows the VCSEL to be operated at higher speeds. Methods of operating the three-terminal VCSEL are also provided. The VCSEL can be operated at higher speeds without decreasing the optical output of the VCSEL when it is in the logical HIGH state.

Abstract: A three-terminal VCSEL is provided that has a reduced fall time that allows the VCSEL to be operated at higher speeds. Methods of operating the three-terminal VCSEL are also provided. The VCSEL can be operated at higher speeds without decreasing the optical output of the VCSEL when it is in the logical HIGH state.

Abstract: This disclosure is concerned with starved source diffusion methods for forming avalanche photodiodes are provided for controlling an edge effect. In one example, a method for manufacturing an avalanche photodiode includes forming an absorber layer and an avalanche layer over a substrate. Next, a patterned mask defining one or more openings is formed over a surface of the avalanche layer. Finally, a dopant is deposited over the patterned mask and the avalanche layer such that the dopant is blocked by the patterned mask but diffuses into the avalanche layer in areas where the patterned mask defines an opening. The patterned mask is configured such that the depth to which the dopant diffuses into the avalanche layer varies so as to form a sloped diffusion front in the avalanche layer.

Abstract: This disclosure is concerned with starved source diffusion methods for forming avalanche photodiodes are provided for controlling an edge effect. In one example, a method for manufacturing an avalanche photodiode includes forming an absorber layer and an avalanche layer over a substrate. Next, a patterned mask defining one or more openings is formed over a surface of the avalanche layer. Finally, a dopant is deposited over the patterned mask and the avalanche layer such that the dopant is blocked by the patterned mask but diffuses into the avalanche layer in areas where the patterned mask defines an opening. The patterned mask is configured such that the depth to which the dopant diffuses into the avalanche layer varies so as to form a sloped diffusion front in the avalanche layer.

Abstract: Starved source diffusion methods for forming avalanche photodiodes (APDs) are provided for controlling the edge effect. The edge effect is controlled by reducing edge gain near the edges of an APD active region. This is accomplished by creating a sloped diffusion front near the edges of the active region. The sloped diffusion front is advantageously formed in a single doping step by using a patterned mask during doping. The patterned mask reduces the depth to which dopants diffuse in areas where it only partly covers the underlying layer. By covering more of the underlying layer nearer the edge and progressively less towards the center, the sloped diffusion front is formed. The shallower diffusion depth near the edge reduces the edge gain, and therefore the edge effect. As a result, an APD to fiber misalignment is less likely, and possibility of edge breakdown is greatly reduced.

Abstract: A vertical cavity apparatus includes first and second mirrors, a substrate and at least first and second active regions positioned between the first and second mirrors. At least one of the first and second mirrors is a fiber with a grating. At least a first tunnel junction is positioned between the first and second mirrors.

Abstract: A vertical cavity apparatus includes first and second mirrors, a substrate, first and second active regions and a plurality of individual active regions. Each of an individual active region is positioned between the first and second active regions. A first oxide layer is positioned between the first mirror and the second mirror. A plurality of tunnel junctions are positioned between the first and second mirrors.

Abstract: A vertical cavity apparatus includes a first mirror, a substrate and a second mirror coupled to the substrate. At least a first and a second active region are each positioned between the first and second mirrors. At least a first oxide layer is positioned between the first and second mirrors. At least a first tunnel junction is positioned between the first and second mirrors.

Abstract: A vertical cavity apparatus includes first and second mirrors, a substrate and at least first and second active regions positioned between the first and second mirrors. A first etched layer is positioned between the first and second mirrors. A first tunnel junction is positioned between the first and second mirrors.

Abstract: A vertical cavity apparatus includes first and second mirrors, a substrate and at least first and second active regions positioned between the first and second mirrors. At least one of the first and second mirrors is a fused mirror. At least a first tunnel junction is positioned between the first and second mirrors.

Abstract: A vertical cavity apparatus includes first and second mirrors, a substrate and at least first and second active regions positioned between the first and second mirrors. At least one of the first and second mirrors is a lattice relaxed mirror. At least a first tunnel junction is positioned between the first and second mirrors.

Abstract: A vertical cavity apparatus includes first and second mirrors, a substrate and at least first and second active regions positioned between the first and second mirrors. At least one of the first and second mirrors is a dielectric mirror. At least a first tunnel junction is positioned between the first and second mirrors.

Abstract: A vertical cavity apparatus includes a first mirror, a substrate and a second mirror coupled to the substrate. At least a first and a second active region are each positioned between the first and second mirrors. At least a first ion implantation layer is positioned between the first and second mirrors. At least a first tunnel junction is positioned between the first and second mirrors.

Abstract: A single mode laser with a laser cavity consisting of an active medium and a first and second reflectors with an antiguide region or layer having a high refractive index positioned adjacent to the laser cavity to bleed off higher order lasing modes and preventing them from attaining the lasing condition. Specifically, light belonging to higher order modes leaks or bleeds into the antiguide region from the laser medium and from the first and second reflectors. When spacers for selecting the desired wavelength of laser light are provided, the light travelling through them leaks into the antiguide layer as well.Optimization of the bleeding of higher order modes into the passive antiguide region can be achieved by adjusting a taper angle of the laser cavity. Furthermore, by adjusting the ratio of the equivalent refractive index of the laser cavity and the passive antiguide region single mode operation at high current levels can be realized for apertures as large as 30 .mu.m.