Applied Optoelectronics, Inc.

Chih-Hsiang Lin

Wen-Yen Hwang

James Nelson Baillargeon

Klaus Alexander Anselm

Jun Zheng

Stefan J Murry

Jeffery L Johnson

N Stephan Kinsella

A multiple reflectivity band reflector (MRBR) includes a stack of dielectric layers, arranged so that the reflector has a reflectivity profile comprising a plurality of reflectivity bands, e.g. at least first and second wavelength bands with reflectivity above a lasing threshold reflectivity, separated by a third wavelength band between the first and second wavelength bands having reflectivity below the lasing threshold reflectivity. A laser having at least a first mirror and an MRBR as the second mirror has a laser cavity, at least a portion of which is defined by the first mirror and the MRBR. An active region located within the laser cavity contains a material that is capable of stimulated emission at one or more wavelengths in the first and second wavelength bands. The gain spectrum of the laser is adjusted to select one of the first and second wavelength bands, thereby providing for lasing at a wavelength within the selected wavelength band. The laser may be, e.g., a monolithic VCSEL or a one-section or two-section external-cavity VECSEL having the MRBR as one of its cavity mirrors.

Multiple reflectivity band reflector

A monitored laser system has a laser having a first mirror; an exit mirror, at least a portion of a laser cavity defined by the first mirror and the exit mirror; and an active region located in the laser cavity, the active region containing a material that is capable of stimulated emission at one or more wavelengths of laser light within a tuning range of the laser. A multiple reflectivity band reflector (MRBR) is coupled to at least a portion of laser light emitted from the laser and transmits filtered laser light. The MRBR has a plurality of layers of material arranged in parallel such that the reflector has a plurality of reflectivity peaks within the tuning range, each reflectivity peak separated from neighboring reflectivity peak by a reflectivity trough having a trough minimum, said reflectivity peaks characterized by a peak profile and said trough minima between said reflectivity peaks characterized by a trough profile. At least one of the peak and trough profiles has a substantially non-constant relationship of wavelength to reflectivity. A first photodiode coupled to at least a portion of the filtered laser light produces an output based on the amount of light received. The emitted wavelength of the laser is adjusted toward a desired wavelength within the tuning range based at least in part on the output of the first photodiode.

Multiple reflectivity band reflector with non-uniform profile and laser system employing same for laser wavelength monitoring

Laser having multiple reflectivity band reflector

A monitored laser system includes a laser with a first mirror and an exit mirror. The laser also has a laser cavity defined at least in part by the first mirror and the exit mirror. Within the laser cavity is an active region that contains material that is capable of stimulated emission at one or more wavelengths such that laser light is emitted from the laser. A power source is coupled to the active region. A multiple reflectivity band reflector (MRBR) is coupled to at least a portion of the emitted laser light. The MRBR has at least first and second wavelength bands with reflectivity above a particular reflectivity separated by at least a third wavelength band having reflectivity below the particular reflectivity. A first photodiode is coupled to at least a portion of the filtered laser light and produces an output based on the amount and wavelength of light received. A means for adjusting the emitted wavelength of the laser toward a particular wavelength in one of the at least first, second, and third wavelength bands based at least in part on the output of the first photodiode.

Method and system employing multiple reflectivity band reflector for laser wavelength monitoring

A planar lightwave circuit (PLC) module for conditioning light output from a tunable laser designed to generate light at a target wavelength. The PLC module has a substrate; a primary waveguide embedded in said substrate, said primary waveguide having an input end for receiving light from the tunable laser and an output end for outputting said light; and at least a first secondary waveguide embedded in said substrate, said first secondary waveguide receiving a first portion of said light from the tunable laser. A filter having a passband centered on the target wavelength is coupled to an output of the first secondary waveguide to receive said first portion of light, and generates a signal related to the intensity of said first portion of light in the passband centered on the target wavelength. This may be used by a processor and associated laser control circuitry for wavelength locking purposes.

Planar lightwave circuit for conditioning tunable laser output

An embodiment of a surface-emitting laser structure includes a first semiconductor region of a first conductivity type coupled to a first contact and a second semiconductor region of the same conductivity type coupled to a second contact. A third semiconductor region of the opposite conductivity type is coupled to a third contact and interposed between the first and second semiconductor regions. An active region is interposed between the first and third regions. In a further embodiment, the laser structure may include a variable refractive index structure interposed between the second and third semiconductor regions. In another embodiment, a surface-emitting laser structure may include an active region between a first semiconductor region of a first conductivity type coupled to a first contact, and a second As semiconductor region of opposite conductivity type coupled to a second contact. A third electrical contact is dielectrically spaced from the second semiconductor region.

Tunable vertical-cavity surface-emitting laser with tuning junction

A vertical-external-cavity surface-emitting laser (VECSEL) is formed by providing a monolithic portion having a first laser cavity mirror and an active region disposed on the first mirror. The cavity is completed with a second laser cavity mirror, such as a DBR, deposited onto the light-receiving end of an optical device, such as an optical fiber. The DBR-on-fiber-end is mounted with respect to the active region to complete the laser cavity and to provide automatic coupling of the output laser light into the fiber.

Optical fiber with mirror for semiconductor laser

An embodiment of a radiation detector includes a semiconductor-based blocking structure interposed between the detector's absorption region and at least one of its contact structures. The blocking structure is adapted to prevent minority carriers generated within the adjacent contact structure from reaching the absorption region, and may also prevent minority carriers generated within the absorption region near the contact structure from entering the contact structure. Majority carriers, on the other hand, may be substantially unimpeded by the blocking structure in moving from the absorption region to the contact structure. In an embodiment, the blocking structure has a higher effective energy gap than its adjacent contact structure and than the absorption region. The interface between the blocking structure and the absorption region may be graded, so that the effective energy gap decreases gradually between the blocking structure and the absorption region.

Double heterostructure photodiode with graded minority-carrier blocking structures

A metal bonded vertical-cavity surface-emitting laser (VCSEL) structure with a bottom dielectric distributed Bragg reflector (DBR) mirror, and method for fabricating the VCSEL structure. The VCSEL structure consists a metal bonding layer disposed on a submount at a bottom side of the metal bonding layer; a bottom cavity mirror comprising a bottom dielectric distributed Bragg reflector (DBR) disposed within the metal bonding layer, the bottom dielectric DBR having a reflectance band including the lasing wavelength; a bottom current-spreading layer disposed on said bottom dielectric DBR and on a substantially flat, annular top surface of said metal bonding layer; a semiconductor active region disposed on the bottom current-spreading layer, said active region capable of stimulated emission at the lasing wavelength; and a top cavity mirror disposed above the active region and having a reflectance band including the lasing wavelength.

Vertical-cavity surface-emitting laser with bottom dielectric distributed bragg reflector

A multispectral radiation detector for detecting radiation in at least two spectral bands, comprises a substrate and a layer stack grown on the substrate. The layer stack comprises at least first and second photodiodes, each photodiode having at least one strain-compensating superlattice absorbing layer substantially lattice matched to adjacent layers of the detector. Each strain-compensating superlattice absorbing layer has an energy gap responsive to radiation energy in a corresponding spectral region and different from the energy gaps of other strain-compensating superlattice absorbing layers of the detector.

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Sugar Land, TX, United States of America

Chih-Hsiang Lin