Sdl Inc.

Jds Uniphase Corporation

Xerox Corporation

Jo S Major

David F Welch

Donald R Scifres

Robert G Waarts

Derek W Nam

David Kirtland Fork

Tae Jin Kim

Robert L Thornton

Robert J Lang

Ross D Bringans

G A Connell

Edmund L Wolak

Victor Rossin

Ross A Parke

Randall S Geels

Stephen O'Brien

Harrison Ransom

Ian J Booth

Radhakrishnan Nagarajan

Hanmin Zhao

Garnet Luick

David C Dawson

Fritz Christo

A high power, single lateral mode semiconductor laser has a waveguide with regions of different widths coupled by a tapered region. The laser has a laterally confining optical waveguide having a highly reflecting first end and a second end. The optical waveguide has a first portion extending from the first end and a second portion extending from the second end. The first and second portions are coupled by a tapered waveguide. A width of the first portion is less than a width of the second portion. The first portion filters lateral optical modes higher than a fundamental lateral optical mode. An output is emitted from the second end of the optical waveguide.

High-power, kink-free, single mode laser diodes

A laser package comprises a laser diode source having a first Fabry-Perot cavity between a highly reflective back facet and low reflective front facet for providing a first light output for an optical application. A light monitor is positioned adjacent to the back facet and aligned to receive a second light output from the laser diode back facet. A pigtail fiber having a lensed fiber input end is positioned from the laser diode front facet to form an optical coupling region and is aligned relative to the lasing cavity to receive the first light output into the fiber, the light output exiting the package for coupling to the application. A portion of the first light output from the lasing cavity is reflected off the lensed fiber input end with a portion directed back into the lasing cavity and another portion reflected off of the laser diode front facet. The front facet forms with the lensed fiber input end a second Fabry-Perot cavity generating light which is periodically in and out of phase with the light generated in the first Fabry-Perot cavity due to changes in the length of the second Fabry-Perot cavity caused by package ambient temperature changes so that a tracking error is generated in a signal developed by the light monitor. Thus, this invention provides several ways to suppress the formation of the second Fabry-Perot cavity.

Tracking error suppression and method of reducing tracking error

Methods are disclosed for forming Group III-arsenide-nitride semiconductor materials. Group III elements are combined with group V elements, including at least nitrogen and arsenic, in concentrations chosen to lattice match commercially available crystalline substrates. Epitaxial growth of these III-V crystals results in direct bandgap materials, which can be used in applications such as light emitting diodes and lasers. Varying the concentrations of the elements in the III-V crystals varies the bandgaps, such that materials emitting light spanning the visible spectra, as well as mid-IR and near-UV emitters, can be created. Conversely, such material can be used to create devices that acquire light and convert the light to electricity, for applications such as full color photodetectors and solar energy collectors. The growth of the III-V crystals can be accomplished by growing thin layers of elements or compounds in sequences that result in the overall lattice match and bandgap desired.

Methods for forming group III-arsenide-nitride semiconductor materials

The effectiveness of reflected light to stabilize the operational characteristics of a semiconductor diode laser varies with the polarization orientation of the reflected light. Stabilization failure can occur if the polarization orientation of the reflected light is orthogonal to the polarization of the light emitted by the laser source. The use of multiple reflectors can reduce the probability of stabilization failure by arranging the reflectors to return to the laser source portions of light having polarization orientations that are statistically independent with respect to each other.

Polarization-insensitive laser stabilization using multiple waveguide gratings

Methods are disclosed for forming Group III--arsenide-nitride semiconductor materials. Group III elements are combined with group V elements, including at least nitrogen and arsenic, in concentrations chosen to lattice match commercially available crystalline substrates. Epitaxial growth of these III-V crystals results in direct bandgap materials, which can be used in applications such as light emitting diodes and lasers. Varying the concentrations of the elements in the III-V crystals varies the bandgaps, such that materials emitting light spanning the visible spectra, as well as mid-IR and near-UV emitters, can be created. Conversely, such material can be used to create devices that acquire light and convert the light to electricity, for applications such as full color photodetectors and solar energy collectors. The growth of the III-V crystals can be accomplished by growing thin layers of elements or compounds in sequences that result in the overall lattice match and bandgap desired.

Methods for forming group III-V arsenide-nitride semiconductor materials

A single transverse mode semiconductor laser diode source is designed for employment in an optical transmission link comprising a transmitter module and a receiver module operable under uncooled conditions, i.e., without the need of costly cooling equipment, such as thermoelectric coolers. The optical transmission system includes both the semiconductor laser diode source and the optical receiver module that are both designed to operate uncooled under high frequencies (e.g., GHz range) over a wide temperature range without significant changes in signal bandwidth and at temperatures in excess of 125.degree. C.

Single transverse mode semiconductor laser for an optical transmission

III-V arsenide-nitride semiconductor are disclosed. Group III elements are combined with group V elements, including at least nitrogen and arsenic, in concentrations chosen to lattice match commercially available crystalline substrates. Epitaxial growth of these III-V crystals results in direct bandgap materials, which can be used in applications such as light emitting diodes and lasers. Varying the concentrations of the elements in the III-V materials varies the bandgaps, such that materials emitting light spanning the visible spectra, as well as mid-IR and near-UV emitters, can be created. Conversely, such material can be used to create devices that acquire light and convert the light to electricity, for applications such as full color photodetectors and solar energy collectors. The growth of the III-V material can be accomplished by growing thin layers of elements or compounds in sequences that result in the overall lattice match and bandgap desired.

III-V arsenide-nitride semiconductor

A harmonic generator laser system which features a distributed Bragg reflector (DBR) or distributed feedback (DFB) tunable diode laser coupled to a quasi-phase matched (QPM) waveguide of optically nonlinear material. Tuning of the DBR laser may be achieved either thermally or via current injection, or both, halving the wavelength of a red laser into the visible blue spectral band. Thermal tuning may provide a coarse tuning adjustment, while injected current may provide fine tuning accessible to a user. Separately or in combination with current tuning, a modulation signal may be applied to the DBR laser for achieving an intensity modulated or a pulsed output. In another embodiment, modulation may be achieved by frequency modulation of the laser. A very compact tunable blue laser is formed. In yet another embodiment a double clad fiber amplifier is disposed between the tunable laser and the waveguide. The fiber amplifier is pumped by a high power laser, while the core guides light to be frequency doubled in the nonlinear material from a continuously tunable laser.

Tunable blue laser diode

Optical semiconductor devices with integrated diffraction gratings with higher quality are realized through the use of Al-free grating layers. AlGaAs/GaAs regime optical semiconductor devices, such as laser diodes or optical filters, conventionally utilize an AlGaAs grating layer that has a strong affinity for oxidation. Instead of a Al-containing layer, a quantenary, InGaAsP grating layer is utilized, lattice matched to the underlying AlGaAs/GaAs structure, substantially eliminating any problem of oxide contamination. Also, an Al-free, ternary InGaP grating layer is utilized in the InGaP/InGaAsP/GaAs material regime. The quantum well active region of these devices may also be modified to extend the gain bandwidth of operation of these devices to insure continued operation over a wider temperature range with the wavelength peak of the grating in that the wavelength peak of the grating more assuredly remains within the wavelength operating range of the device.

Optical semiconductor device with diffraction grating structure

An AlGaInP/GaAs laser diode is disclosed in which the active region is made up of quantum wells that are sufficiently thin (less than 5 nm thick) that the transition energy increase due to quantum confinement of the carriers becomes significant. This allows the quantum well material composition to be selected for compressive strain so that the laser operates in the TE polarization mode, while still obtaining a transition energy of from 1.9-2.0 eV for 620-650 nm laser emission. Quantum barriers have sufficient thickness to confine carriers to the quantum wells. Self-pulsation may be obtained in a heterostructure that also includes a saturable absorption layer proximate to the active region and a ridge structure transversely confining absorption produced carriers in the central section of the absorber layer, while allowing lateral carrier diffusion to side regions where carriers are allowed to leave the absorber layer.

Transverse electric (TE) polarization mode AlGaInP/GaAs red laser

An optical transmission link has both a transmitter module and a receiver module operable under uncooled conditions, i.e., without the need of costly cooling equipment, such as thermoelectric coolers. The optical transmission system includes both a semiconductor laser diode source and an optical receiver module that are both designed to operate uncooled under high frequencies (e.g., GHz range) over a wide temperature range without significant changes in signal bandwidth and at temperatures in excess of 125.degree. C. Compensation is provided to reduce the effect of photodiode noise and amplifier noise. In addition, temperature compensation can be provided that provides for overall reduction in receiver noise across the bandwidth of the receiver module through maintenance of a temperature environment optimizing receiver performance.

Optical transmission link capable of high temperature operation without

III-V arsenide-nitride semiconductor crystals, methods for producing such crystals and devices employing such crystals. Group III elements are combined with group V elements, including at least nitrogen and arsenic, in concentrations chosen to lattice match commercially available crystalline substrates. Epitaxial growth of these III-V crystals results in direct bandgap materials, which can be used in applications such as light emitting diodes and lasers. Varying the concentrations of the elements in the III-V crystals varies the bandgaps, such that materials emitting light spanning the visible spectra, as well as mid-IR and near-UV emitters, can be created. Conversely, such material can be used to create devices that acquire light and convert the light to electricity, for applications such as full color photodetectors and solar energy collectors. The growth of the III-V crystals can be accomplished by growing thin layers of elements or compounds in sequences that result in the overall lattice match and bandgap desired.

III-V aresenide-nitride semiconductor materials and devices

A harmonic generator laser system which features a distributed Bragg reflector (DBR) or distributed feedback (DFB) tunable diode laser coupled to a quasi-phasematched (QPM) waveguide of optically nonlinear material. Tuning of the DBR laser may be achieved either thermally or via current injection, or both, halving the wavelength of a red laser into the visible blue spectral band. Thermal tuning may provide a coarse tuning adjustment, while injected current may provide fine tuning accessible to a user. Separately or in combination with current tuning, a modulation signal may be applied to the DBR laser for achieving an intensity modulated or a pulsed output. In another embodiment, modulation may be achieved by frequency modulation of the laser. A very compact tunable blue laser is formed. In yet another embodiment a double clad fiber amplifier is disposed between the tunable laser and the waveguide. The fiber amplifier is pumped by a high power laser, while the core guides light to be frequency doubled in the nonlinear material from a continuously tunable laser.

A monolithic multi-wavelength laser diode array having a composite active region of at least two dissimilar quantum well layers that are partially mixed in at least one of their constituent atomic species in at least one area of the active region. Different areas of the active region are characterized by different emission wavelengths determined by the degree of intermixing. An impurity free interdiffusion, such as vacancy enhanced interdiffusion, is used to provide the intermixing. Each area may have one or more waveguides and distributed Bragg reflector gratings tuned to the emission wavelength of the corresponding area of the active region. Each area or waveguide may also be separately pumped with an individually addressable current injection electrode. The laser output may be coupled into a ferroelectric frequency doubler integrally formed on the array substrate. The frequency doubler has periodically poled waveguides for quasi-phase matching in front of areas of the laser array emitting light which is to be doubled in frequency.

Growing community of inventors

San Jose, CA, United States of America

Jo S Major