Abstract: A method of fabricating a semiconductor laser device by forming a semiconductor structure at least part of which is in the form of a mesa structure having a flat top. The steps include depositing a passivation layer over the mesa structure, forming a contact opening in the passivation layer on the flat top of the mesa structure; and depositing a metal contact portion, with the deposited metal contact portion contacting the semiconductor structure via the contact opening. The contact opening formed through the passivation layer has a smaller area than the flat top of the mesa structure to allow for wider tolerances in alignment accuracy. The metal contact portion comprises a platinum layer between one or more gold layers to provide an effective barrier against Au diffusion into the semiconductor material.

Abstract: A semiconductor device including a semiconductor substrate having a surface including an active semiconductor device including one of a laser and a photodiode; and a visual indicator disposed on the semiconductor body and at least adjacent to a portion of said active semiconductor device, the indicator having a state that shows if damage to the active semiconductor device may have occurred.

Abstract: According to an embodiment of the invention, there is provided a micro integratable tunable laser assembly (m-ITLA) which includes an electrical interface for interfacing with a host, a tunable laser module for conducting optical communication, and a control unit, for at least controlling operation of the tunable laser module according to information received from the host via the electrical interface. The m-ITLA can have a length of about 37 mm or less and a width of about 20 mm or less.

Abstract: An apparatus for analyzing, identifying or imaging an target including first and second laser beams coupled to a pair of photoconductive switches to produce CW signals in one or more bands in a range of frequencies greater than 100 GHz focused on and transmitted through or reflected from the target; and a detector for acquiring spectral information from signals received from the target and using a multi-spectral heterodyne process to generate an electrical signal representative of some characteristics of the target. The lasers are tuned to different frequencies and a frequency shifter in the path of one laser beam allows the terahertz beam to be finely adjusted in one or more selected frequency bands.

Abstract: A tunable laser configured in a small package coupled to a printed circuit board. The tunable laser includes a housing with a volume formed by exterior walls. An electrical input interface is positioned at the first end of the housing. An optical output interface is positioned at the second end of the housing and configured to transmit a continuous wave optical beam. A beam splitter and photodiode is disposed in the path of the laser beam for determining the emitted intensity of the laser beam, and an optical isolator is positioned downstream of the beam splitter to prevent the incoming light from the beam splitter from reflecting back though the beam splitter and into the cavity of the laser.

Abstract: A laser assembly and a method for manufacturing the same are provided according to embodiments of the present disclosure. The laser assembly (900) may comprise a first plate (903) having first projections (918, 928); a printed circuit board assembly (902) including a printed circuit board (912) having first openings (913, 915) and a laser module (100) thereon, and a second plate (901) having second projections (917, 927). The printed circuit board assembly (902) can be retained between the first plate (903) and the second plate (901) by the first projections (918, 928) and the second projections (917, 927). The laser assembly may further comprises a first pad (930) provided between the laser module (100) and the first plate (903) and/or a second pad (920) provided between the laser module (100) and the second plate (901).

Abstract: A semiconductor gain device comprising a substrate; an optical waveguide layer extending from a first end of the substrate to a second end of the substrate opposite to the first end, the optical waveguide layer including an active layer formed on the upper surface; a reflective mirror provided at one end of the optical waveguide layer, and an exit aperture on the other end of the optical waveguide layer for emitting optical energy; wherein at least a portion of the optical waveguide layer is curved on the surface of the substrate from the first end to the second end with a radius of curvature of less than 4 mm.

Abstract: A laser assembly and a method for manufacturing the same are provided according to embodiments of the present disclosure. The laser assembly (900) may comprise a first plate (903) having first projections (918, 928); a printed circuit board assembly (902) including a printed circuit board (912) having first openings (913, 915) and a laser module (100) thereon, and a second plate (901) having second projections (917, 927). The printed circuit board assembly (902) can be retained between the first plate (903) and the second plate (901) by the first projections (918, 928) and the second projections (917, 927). The laser assembly may further comprises a first pad (930) provided between the laser module (100) and the first plate (903) and/or a second pad (920) provided between the laser module (100) and the second plate (901).

Abstract: A method of making an optical modulator by determining the material composition of the quantum well region in the waveguide portion of the modulator so that the modulator is transparent at a gain peak wavelength that is greater than the predetermined wavelength by a predetermined amount, and fabricating the modulator with the determined material composition.

Abstract: An apparatus for analyzing, identifying or imaging an target including first and second laser beams coupled to a pair of photoconductive switches to produce CW signals in one or more bands in a range of frequencies greater than 100 GHz focused on and transmitted through or reflected from the target; and a detector for acquiring spectral information from signals received from the target and using a multi-spectral heterodyne process to generate an electrical signal representative of some characteristics of the target. The lasers are tuned to different frequencies and a frequency shifter in the path of one laser beam allows the terahertz beam to be finely adjusted in one or more selected frequency bands.

Abstract: There is discussed an optical system comprising a laser device that outputs a divergent light beam. A first portion of the divergent light beam, including a central portion, passes through an etalon device, which acts as a wavelength discriminator, and then the central portion is incident on a first monitor photodiode, which generates a wavelength-dependent detection signal. A second portion of the divergent light beam is incident on a second monitor photodetector, without passing through the etalon device, to generate a wavelength-independent detection signal. A processor processes the wavelength-dependent detection signal and the wavelength-independent detection signal to determine a control signal for controlling the wavelength of the laser device. By accurately positioning a photodetector at the central fringe of the divergent light beam following transmission through the etalon device, a compact and cost-effective wavelength locking arrangement is provided.

Abstract: A fiber optic gyroscope including a non-coherent light source for producing a first beam of light, an optical circulator in the path of said first beam for providing polarized second and third beams, respectively, with polarization orthogonal to each other, and a time division multiplexer in the path of the second and third beams. A first planar optical fiber loop is coupled to the time division multiplexer and has a first end and a second end coupled to the second and third beams respectively during a first time period. A second planar optical fiber loop is coupled to the time division multiplexer and has a first end and a second end coupled to the second and third beams respectively during a second time period subsequent to the first time period.

Abstract: Methods of attaching an optical line to a phase modulator in a fiber optic gyroscope. The methods include positioning at least one end of the optical line relative to a side of the phase modulator. The end of the optical line may have a first non-perpendicular angle and the side of the phase modulator may have a second non-perpendicular angle. The end of the optical line may be attached to the side of the phase modulator with the end of the optical line being non-parallel to the side of the phase modulator. The optical line may be an optical coil or a light path.

Abstract: There is discussed an optical system comprising a laser device that outputs a divergent light beam. A first portion of the divergent light beam, including a central portion, passes through an etalon device, which acts as a wavelength discriminator, and then the central portion is incident on a first monitor photodiode, which generates a wavelength-dependent detection signal. A second portion of the divergent light beam is incident on a second monitor photodetector, without passing through the etalon device, to generate a wavelength-independent detection signal. A processor processes the wavelength-dependent detection signal and the wavelength-independent detection signal to determine a control signal for controlling the wavelength of the laser device. By accurately positioning a photodetector at the central fringe of the divergent light beam following transmission through the etalon device, a compact and cost-effective wavelength locking arrangement is provided.

Abstract: A compact fiber optic gyroscope including a first housing; a transceiver module disposed in the first housing, the transceiver module including a second housing; a non-coherent light source disposed in the second housing for producing a first beam of light; a single lens for focusing the first beam of light; an optical circulator disposed in the second housing and in the path of the first beam of light to produce polarized second and third beams respectively, with polarization orthogonal to each other; and first and second photodiodes disposed in the second housing and coupled to the optical circulator, wherein the first photodiode is a transmit monitor photodiode coupled to the second beam, and the second photodiode is a receiver photodiode.

Abstract: A GPON module comprises a housing and a circuit board disposed in the housing. The circuit board further includes ground lines that substantially isolate regions of the circuit board, an electro-optical interface for converting an inbound optical signal to an electrical signal and processing circuitry that is arranged to provide an electrical RF signal to an RF interface. The RF interface comprises a three-pin RF connector exposed from the housing, wherein the RF connector is coupled directly to the circuit board, and two of the three pins are coupled to ground.

Abstract: Disclosed herein is a method of detecting a contaminant material in a food sample. The method includes irradiating a food sample with a beam of electromagnetic radiation, the beam having a plurality of frequencies in the range of about 100 GHz to about 2 THz; detecting radiation transmitted and/or reflected from the food sample; and, analyzing the detected radiation to determine the presence of contaminant material. The contaminant material may be melamine, cyanuric acid, ammeline, or ammelide.

Abstract: An optical transmitter for generating a modulated optical signal for transmission over dispersive fiber optic links in which a first information-containing radio frequency signal input is applied to a modulation circuit for directly modulating a semiconductor laser with the signal input. The output of the laser is applied to a phase modulator to which a second information-containing radio frequency signal is applied.

Abstract: An optical communication system for generating and transmitting a modulated optical signal in which light emitted by a light source is modulated by an optical modulator in accordance with an input electrical signal. A bias signal generator applies a bias electrical signal to bias the optical modulator at a bias angle away from quadrature. The bias signal generator monitors the input electrical signal and adjusts the applied bias electrical signal in dependence on the input electrical signal. The system further includes a receiver which may include an equalizer coupled to the photodetector of the receiver.

Abstract: A method of fabricating a semiconductor laser device by forming a semiconductor structure at least part of which is in the form of a mesa structure having a flat top. The steps include depositing a passivation layer over the mesa structure, forming a contact opening in the passivation layer on the flat top of the mesa structure; and depositing a metal contact portion, with the deposited metal contact portion contacting the semiconductor structure via the contact opening. The contact opening formed through the passivation layer has a smaller area than the flat top of the mesa structure to allow for wider tolerances in alignment accuracy. The metal contact portion comprises a platinum layer between one or more gold layers to provide an effective barrier against Au diffusion into the semiconductor material.