Abstract: The invention discloses a multi-wavelength semiconductor light source comprising a plurality of semiconductor light sources mounted on a silicon sub-carrier and emitting radiation spanning a wavelength range. In preferred embodiments, these sources are configured in a linear and circular array. The radiation is coupled to a waveguide array disposed on the same silicon subcarrier, with a lower cladding of silicon dioxide and deposited core layer which is preferably the spin-on epoxy resin SU-8. Output from the waveguide array provides a compact multi-wavelength laser source with wide tuning range via a plurality of laser sources. An output spatial span of the waveguide array is smaller than an input spatial span and sufficiently small to probe the properties of a sample.

Abstract: A superluminescent diode according the present invention employs a unoform AlGaInAs quantum well on an InP substrate, emitting in a range of 1100 to 1800 nm. The favorable conduction band: valence band offset ratio of this material system enables superluminescent diodes which simultaneously provide high power and large optical bandwidth. A recent reduction to practice of the present invention simultaneously demonstrates output power exceeding 100 mW and bandwidth exceeding 100 nm. A preferred embodiment of this invention uses multiple uniform AlGaInAs quantum wells with two confined quantum states and energetic separation in a range of 100-130 nm. An alternate preferred embodiment uses non-uniform wells, with each well having two confined quantum states. The present invention is particularly useful in time domain and spectral domain optical coherence tomography systems, providing increased resolution and tissue penetration for in-vivo imaging.

Abstract: A swept source Optical coherence tomography system (SSOCT) comprises a vertical cavity surface-emitting laser with an integrated MEMs tunable mirror movable by electro-static deflection. The MEMs tunable VCSEL offers scan rates greater than 100 khz and tuning ranges approaching 200 nm around 1300 nm and 150 nm around 850 nm. In the preferred embodiment of this invention, a bottom mirror of the VCSEL is comprised of a Aluminum Gallium Arsenide/Aluminum Oxide DBR stack, and a movable top mirror is comprised of a TiO2/SiO2 DBR stack. A MEMs tunable VCSEL at 1300 nm is preferably pumped through the top mirror in a wavelength range between 1050 and 1120 nm, and a MEMs tunable VCSEL at 850 nm is preferably pumped through the top mirror in a wavelength range between 700 nm and 730 nm.

Abstract: A swept source Optical coherence tomography system (SSOCT) comprises a vertical cavity surface-emitting laser with an integrated MEMs tunable mirror movable by electro-static deflection. The MEMs tunable VCSEL offers scan rates greater than 100 khz and tuning ranges approaching 200 nm around 1300 nm and 150 nm around 850 nm. In the preferred embodiment of this invention, a bottom mirror of the VCSEL is comprised of a Aluminum Gallium Arsenide/Aluminum Oxide DBR stack, and a movable top mirror is comprised of a TiO2/SiO2 DBR stack. A MEMs tunable VCSEL at 1300 nm is preferably pumped through the top mirror in a wavelength range between 1050 and 1120 nm, and a MEMs tunable VCSEL at 850 nm is preferably pumped through the top mirror in a wavelength range between 700 nm and 730 nm.

Abstract: A compact laser spectrometer according to the present invention includes a plurality of semiconductor lasers comprising a plurality of semiconductor gain medium compositions emitting a plurality of radiation components originating from an area having a maximum transverse dimension that is smaller than a minimum feature size of a sample. A broadband optical detector detects a diffuse reflectance. In one preferred embodiment of this invention the plurality of semiconductor lasers consists of Fabry-Perot edge-emitting lasers arranged around the perimeter of a cylindrical submount with a substantially circular cross-section. The plurality of radiation components is directly coupled to a multi-mode optical fiber, which presents radiation to a sample. In another preferred embodiment a linear array of Fabry-Perot edge-emitting lasers is directly coupled to a multi-mode fiber.

Abstract: A tunable laser according to the present invention includes a plurality of Fabry-Perot semiconductor lasers comprising a plurality of semiconductor gain medium compositions disposed on a common sub-carrier with means for thermal tuning, and coupled to a sample. In a preferred embodiment, the lasers are coupled to a common multi-mode optical fiber, and an output radiation from the multi-mode fiber is tunable by switching the drive current amongst the lasers, and by thermal tuning of each laser in the array. In one preferred embodiment of this invention the plurality of Fabry-Perot semiconductor lasers are arranged around the perimeter of a cylindrical submount with a substantially circular cross-section. In another preferred embodiment a linear array of Fabry-Perot edge-emitting lasers is directly coupled to a multi-mode fiber. In still another preferred embodiment, an array of Fabry-Perot lasers is coupled to a fiber bundle.

Abstract: A semiconductor laser-based spectrometer according to the present invention includes a plurality of semiconductor lasers comprising a plurality of semiconductor gain medium compositions directly coupled to a large-core multi-mode fiber with no intervening optics. An output radiation from the multi-mode fiber is tunable by switching the drive current amongst the lasers, and by thermal tuning of each laser in the array. In combination with presentation to a sample, and means for detection of a diffuse reflectance or transmittance, this assembly functions as a compact, high signal to noise ratio, fast measurement spectrometer. In one preferred embodiment of this invention the plurality of semiconductor lasers consists of Fabry-Perot edge-emitting lasers arranged around the perimeter of a cylindrical submount with a substantially circular cross-section. In another preferred embodiment a linear array of Fabry-Perot edge-emitting lasers is directly coupled to a multi-mode fiber.

Abstract: A semiconductor wafer according to the present invention has multiple epitaxial regions comprising planar epitaxial surfaces and edge surfaces, where the planar epitaxial surfaces are wafer bonded at different lateral positions to a host substrate, and an edge surface of each epitaxial region is bonded to an edge surface of an adjacent epitaxial region. This enables the fabrication of photonic integrated circuits that traverse the different regions, providing previously unattainable functionality, performance, or level of integration. The method of achieving this includes placing sections cleaved from various source wafers onto a single common host substrate, and applying a combination of vertical and lateral pressure to achieve bonding of both planar surfaces and edge surfaces.

Abstract: A semiconductor opto-electronic device according to the present invention has a grating disposed at an electrically passive wafer bonded interface. The device has p and n contacts, and current path between the contacts that does not traverse the wafer bonded interface. The absence of current injection across defective interfaces leads to a device with improved reliability relative to prior art regrowth approaches. The present invention can be combined with vertical and lateral wafer bonding to create grating-based devices with an active/passive transition, such as tunable lasers.

Abstract: A method of forming a semiconductor substrate having a plurality of epitaxial regions disposed at different lateral locations, includes assembling a plurality of epitaxial layers vertically adjacent to each other on a host substrate to form an epitaxial structure; etching a surface of the epitaxial structure to reveal epitaxial regions of the epitaxial layers at different lateral locations on the host substrate; and wafer bonding the etched surface of the epitaxial structure to a transfer substrate.

Abstract: A process for use in fabrication of a semiconductor device is disclosed. The fabricated semiconductor device includes a top oxide aperture within a top oxidation layer and a bottom oxide aperture within a bottom oxidation layer precisely positioned relative to each other, and an electrical contact to a contact layer between the top and bottom oxidation layers. The process includes the following steps: etching past one of the oxidation layers and stopping in the contact layer, etching one or more holes traversing the top and bottom oxidation layers, and simultaneously oxidizing both oxidation layers. Etching past both oxidation layers in the same alignment step ensures that the centers of the two apertures, as formed through selective oxidation, will be aligned.

Abstract: A semiconductor device includes an array of long-wavelength VCSELs pumped by a short-wavelength optical pump. The array of long-wavelength VCSELs includes a series of semiconductor recesses, where each semiconductor recess is between two layers of a VCSEL, substantially overlapping the transverse model profile of the VCSEL under operation.

Abstract: A process for use in fabrication of a semiconductor device is disclosed. The fabricated semiconductor device includes a top oxide aperture within a top oxidation layer and a bottom oxide aperture within a bottom oxidation layer precisely positioned relative to each other, and an electrical contact to a contact layer between the top and bottom oxidation layers. The process includes the following steps: etching past one of the oxidation layers and stopping in the contact layer, etching one or more holes traversing the top and bottom oxidation layers, and simultaneously oxidizing both oxidation layers. Etching past both oxidation layers in the same alignment step ensures that the centers of the two apertures, as formed through selective oxidation, will be aligned.

Abstract: A process for use in fabrication of a semiconductor device is disclosed. The fabricated semiconductor device includes a top oxide aperture within a top oxidation layer and a bottom oxide aperture within a bottom oxidation layer precisely positioned relative to each other, and an electrical contact to a contact layer between the top and bottom oxidation layers. The process includes the following steps: etching past one of the oxidation layers and stopping in the contact layer, etching one or more holes traversing the top and bottom oxidation layers, and simultaneously oxidizing both oxidation layers. Etching past both oxidation layers in the same alignment step ensures that the centers of the two apertures, as formed through selective oxidation, will be aligned.

Abstract: A compact WDM optical device can demultiplex an optical laser signal containing several different wavelengths corresponding to particular channels, and, in reverse operation operate as a multiplexer to interleave several different wavelengths into a multiplexed multi-channel optical laser signal with improved insertion loss characteristics. The optical device includes a linear array of passive resonant optical cavities, in the form of Fabry-Perot filters, extending in a lateral direction and an integral array of associated microlenses extending in the lateral direction. Each microlens has a center which is offset from the central longitudinal axis of an associated Fabry-Perot filter to reflect laser radiation through the device. Each optical cavity is tuned by adjusting the longitudinal dimension thereof to a particular wavelength contained in the multi-channel optical signal. A stepped-wavelength steered laser radiation source for the optical device uses a VCSEL array with offset microlenses.

Abstract: In the fabrication of vertical cavity surface emitting lasers, patterned wafer fusion promotes low-loss refractive index guiding combined with a mechanically robust and reproducibly fabricatable structure. A fabricated laterally refractive index guided VCSEL includes a plurality of layers of semiconductor, including a bottom mirror stack disposed above a semiconductor substrate, an active region having upper and lower claddings sandwiching a layer of quantum wells disposed above the bottom mirror stack, and a top mirror stack disposed above the active region. A recessed pattern is etched in one of the plurality of layers to create a mode confining layer, prior to wafer fusion, which forms a buried air gap subsequent to wafer fusion. The buried air gap provides a lateral refractive index profile, which functions as a low-loss means for index guiding the VCSEL optical energy to the single fundamental transverse mode.

Abstract: An optoelectronic module includes one or more VCSEL transmitters and/or photodetectors coincidentally aligned along a common central longitudinal axis. Differing wavelengths of light can be received and transmitted by the optoelectronic module optically coupled to a single optical fiber or in a free-space link. The optoelectronic module is able to receive two wavelengths and transmit one wavelength, or can transmit two wavelengths in the optical link. The VCSEL transmitter can be optically pumped by a vertically integrated pump VCSEL. A parallel optical link supports transmission and reception for each duplex channel on a single optical fiber.

Abstract: A compact WDM optical device can demultiplex an optical laser signal containing several different wavelengths corresponding to particular channels, and, in reverse operation operate as a multiplexer to interleave several different wavelengths into a multiplexed multi-channel optical laser signal with improved insertion loss characteristics. The optical device includes a linear array of passive resonant optical cavities, in the form of Fabry-Perot filters, extending in a lateral direction and an integral array of associated microlenses extending in the lateral direction. Each microlens has a center which is offset from the central longitudinal axis of an associated Fabry-Perot filter to reflect laser radiation through the device. Each optical cavity is tuned by adjusting the longitudinal dimension thereof to a particular wavelength contained in the multi-channel optical signal. A stepped-wavelength steered laser radiation source for the optical device uses a VCSEL array with offset microlenses.

Abstract: An electrically-pumped short wavelength vertical cavity surface emitting laser (VCSEL) is optically coupled to a long wavelength VCSEL for optically pumping the long wavelength VCSEL. The long wavelength VCSEL has a long wavelength active-absorber medium interposed between a top long wavelength mirror and a bottom long wavelength mirror. The long wavelength VCSEL emits radiation at a first wavelength in a range from 1250 nm to 1650 nm. The short wavelength VCSEL emits radiation at a second wavelength in a range from 700 nm to 1050 nm.

Abstract: A long wavelength VCSEL according to the present invention is optically coupled to and optically pumped by a shorter wavelength, electrically pumped VCSEL. Short wavelength radiation emitted from the top surface of the underlying VCSEL is transmitted through the lower mirror of the long wavelength VCSEL. Long wavelength radiation is preferably emitted from the top surface of the long wavelength VCSEL. The two VCSELs are preferably joined together using a transparent optical adhesive, a wafer-fusing process, or a metal to metal bond.