Bandgap Technology Corporation

The United States of America As Represented by the Secretary of

Other

The United States of America As Represented by the United States

Vixel Corporation

Gregory R Olbright

Jack L Jewell

Robert P Bryan

Richard P Schneider, Jr

Kevin L Lear

Jeffrey Y Tsao

Thomas M Brennan

Peter Esherick

James A Lott

A vertical-cavity surface-emitting laser is disclosed comprising a laser cavity sandwiched between two distributed Bragg reflectors. The laser cavity comprises a pair of spacer layers surrounding one or more active, optically emitting quantum-well layers having a bandgap in the visible which serve as the active optically emitting material of the device. The thickness of the laser cavity is m .lambda./2n.sub.eff where m is an integer, .lambda. is the free-space wavelength of the laser radiation and n.sub.eff is the effective index of refraction of the cavity. Electrical pumping of the laser is achieved by heavily doping the bottom mirror and substrate to one conductivity-type and heavily doping regions of the upper mirror with the opposite conductivity type to form a diode structure and applying a suitable voltage to the diode structure. For radiation in the yellow to green portion of the spectrum, the laser includes an active layer of GaP or AlGaP quantum wells and AlP/AlGaP mirrors. For radiation in the blue portion of the spectrum, the laser includes an active region of InGaN or GaN quantum wells and AlN/AlGaN mirrors.

Visible light surface emitting semiconductor laser

A monolithically integrated optoelectronic device is provided which integrates a vertical cavity surface emitting laser and either a photosensitive or an electrosensitive device either as input or output to the vertical cavity surface emitting laser either in parallel or series connection. Both vertical and side-by-side arrangements are disclosed, and optical and electronic feedback means are provided. Arrays of these devices can be configured to enable optical computing and neural network applications.

Integration of photoactive and electroactive components with vertical

A vertical cavity surface emitting laser that emits visible radiation is built upon a substrate, then having mirrors, the first mirror on top of the substrate; both sets of mirrors being a distributed Bragg reflector of either dielectrics or other materials which affect the resistivity or of semiconductors, such that the structure within the mirror comprises a plurality of sets, each having a thickness of .lambda./2n where n is the index of refraction of each of the sets; each of the mirrors adjacent to spacers which are on either side of an optically active bulk or quantum well layer; and the spacers and the optically active layer are from one of the following material systems: In.sub.z (Al.sub.y Ga.sub.1-y).sub.1-z P, InAlGaAs, AlGaAs, InGaAs, or AlGaP/GaP, wherein the optically active region having a length equal to m .lambda./2n.sub.eff where m is an integer and n.sub.eff is the effective index of refraction of the laser cavity, and the spacer layer and one of the mirrors being transmissive to radiation having a wavelength of .lambda./n, typically within the green to red portion of the visible spectrum.

Visible light emitting vertical cavity surface emitting lasers

A photodetector that is responsive to a wavelength or wavelengths of interest which have heretofore been unrealized. The photodetector includes a resonant cavity structure bounded by first and second reflectors, the resonant cavity structure being resonant at the wavelength or wavelengths of interest for containing a plurality of standing waves therein. The photodetector further includes a radiation absorbing region disposed within the resonant cavity structure, the radiation absorbing region including a plurality of radiation absorbing layers spaced apart from one another by a distance substantially equal to a distance between antinodes of adjacent ones of the standing waves. Each of radiation absorbing layers is spatially positioned at a location of one of the antinodes of one of the standing waves such that radiation absorption is enhanced. The radiation absorbing layers may be either bulk layers or quantum wells includes a plurality of layers, each of which is comprised of a strained layer of InGaAs. Individual ones of the InGaAs layers are spaced apart from one another by a GaAs barrier layer.

Photodetector with absorbing region having resonant periodic absorption

A visual display system is disclosed which utilizes one- and/or two-dimensional arrays of visible emitting vertical-cavity surface-emitting lasers (VCSELs) in order to provide a desired visual display within an observer's field of view. Sweep and subscanning techniques are employed, individually or in combination, to create a full M.times.N image from 1.times.L or K.times.L arrays of VCSELs, where M and N are multiple integers of K and L, respectively. Preferably, the VCSELs are contained within a display housing which may be attached to the head of the user by an attachment mechanism or may alternatively be hand held or mounted to a surface. The circular symmetry and low divergence of the emitted VCSEL radiation as well as the availability of multiple wavelengths, particularly, red, blue and green, allow high resolution monochrome or color images to be generated.

Vertical-cavity surface emitting laser assay display system

Optoelectronic integrated circuits are disclosed comprising a vertical-cavity surface emitting laser (VCSEL) and a transistor. The VCSEL comprises a laser cavity sandwiched between two distributed Bragg reflectors. The laser cavity comprises a pair of spacer layers surrounding one or more active, optically emitting quantum-well layers having a bandgap in the visible range which serve as the active optically emitting material of the device. The thickness of the laser cavity is m .lambda./2n.sub.eff where m is an integer, .lambda. is the free-space wavelength of the laser radiation and n.sub.eff is the effective index of refraction of the cavity. Electrical pumping of the laser is achieved by heavily doping the bottom mirror and substrate to one conductivity-type and heavily doping the regions of the upper mirror with the opposite conductivity type to form a diode structure and applying a suitable voltage to the diode structure. Embodiments are disclosed which integrate the VCSEL with bipolar and FET transistors as well as phototransistors.

Integration of transistors with vertical cavity surface emitting lasers

A three-dimensional optical interconnection is disclosed having a stack of vertically aligned optoelectronic integrated (OEIC) modules. Each OEIC module includes an array of vertical cavity surface emitting lasers (VCSEL), receivers and electronic logic which are monolithically integrated on a single semiconductor substrate. Communication between the OEIC modules is effectuated by the free space propagation of laser radiation from the VCSELs to corresponding receivers on an adjacent OEIC module. Transistors, such as heterojunction bipolar transistors, may be used to drive the VCSELS.

Vertical-cavity surface emitting laser optical interconnect technology

A vertical-cavity surface-emitting laser is disclosed comprising a laser cavity sandwiched between two distributed Bragg reflectors. The laser cavity comprises a pair of spacer layers surrounding one or more active, optically emitting quantum-well layers having a bandgap in the visible which serve as the active optically emitting material of the device. The thickness of the laser cavity is m .lambda./2n.sub.eff where m is an integer, .lambda. is the free-space wavelength of the laser radiation and n.sub.eff is the effective index of refraction of the cavity. Electrical pumping of the laser is achieved by heavily doping the bottom mirror and substrate to one conductivity-type and heavily doping regions of the upper mirror with the opposite conductivity type to form a diode structure and applying a suitable voltage to the diode structure. Specific embodiments of the invention for generating red, green, and blue radiation are described.

Vertical-cavity surface-emitting lasers (VCSELs) are disclosed having various intra-cavity structures to achieve low series resistance, high power efficiencies, and TEM.sub.00 mode radiation. In one embodiment of the invention, a VCSEL comprises a laser cavity disposed between an upper and a lower mirror. The laser cavity comprises upper and lower spacer layers sandwiching an active region. A stratified electrode for conducting electrical current to the active region is disposed between the upper mirror and the upper spacer. The stratified electrode comprises a plurality of alternating high and low doped layers for achieving low series resistance without increasing the optical absorption. The VCSEL further comprises a current aperture as a disk shaped region formed in the stratified electrode for suppressing higher mode radiation. The current aperture is formed by reducing or eliminating the conductivity of the annular surrounding regions. In another embodiment, a metal contact layer having an optical aperture is formed within the upper mirror of the VCSEL. The optical aperture blocks the optical field in such a manner that it eliminates higher transverse mode lasing.

Growing community of inventors

Boulder, CO, United States of America

Gregory R Olbright