Abstract: A surface-emitting distributed feedback (SEDFB) laser is provided with a “fan-shaped” grating comprising a group of generally straight lines radiating from a central point that is away from the center of the gain. Such a grating provides better stability against self-induced filamentation and dynamic instabilities that limit achievable beam quality, especially in lasers having a stripe length greater than 1 mm.

Abstract: A pulse emitting laser is constantly controlled while recording data continuously to a desired power level without using test emissions or a high speed sample hold filter. The laser drive method detects beam emission power from a light source and generates a monitor wave; receives data and generates an expected wave for the beam power based on the received data; calculates the difference between the generated monitor wave and the expected wave; controls current flow from the bias current source based on the calculated waveform difference; and finally emits a beam from the light source based on the controlled current flow of the bias current source.

Abstract: A high performance single-wavelength semiconductor laser device having stable and high-speed operation includes an active region, a forward light reflection region located in front of the active region, a backward light reflection region located behind the active region, and a phase control region located in proximity to the active layer, all sandwiched between an upper cladding layer and a lower cladding layer. The forward light reflection region and the backward light reflection region include alternate diffraction grating portions and non-diffracting portions alternately. The laser oscillates at a wavelength which corresponds to the current flowing in the diffraction grating portion. A current blocking layer is located on the non-diffracting portion of at least one of the forward light reflection region and the backward light reflection region for blocking current from flowing into the non-diffracting portion.

Abstract: A surface emitting semiconductor laser includes an active region formed on a growth substrate, upper and lower mirror layers that sandwich the active region to construct a vertical cavity, a selective oxidization layer, and a current injecting unit for injecting a current into the active region. The selective oxidization layer is selectively oxidized and insulated and is provided on the side of the active region opposite to the side of the substrate. In this structure, a post portion is formed by removing semiconductor material formed on the substrate down to an uppermost or halfway level of the selective oxidization layer while the selective oxidization layer is used as an etch stop layer, and the selective oxidization layer acts as both a current confinement layer for the current injection and an insulating layer for the current injecting unit.

Abstract: A backward laser beam radiated from a laser diode is received in a photo diode, and an intensity of a forward laser beam radiated from the laser diode is adjusted according to the intensity of the received backward laser beam. The forward laser beam radiated from the laser diode is collimated in a first lens held by a lens holder, and a most portion of the forward laser beam is output through a package window inclined with respect to an optical axis of the laser diode. The remaining portion of the forward laser beam is reflected on the package window as a reflected laser beam and is transmitted through the first lens to be converged in a narrow area placed above the laser diode. A light shielding plate extending in a plane orthogonal to the optical axis is arranged in a wide area including the narrow area and shields the photo diode from the reflected laser beam from. Therefore, the intensity of the forward laser beam radiated from the laser diode is correctly adjusted.

Abstract: Two or more laser diodes are combined by crossing their cavities, and the multiple lasers share a common outcoupling aperture. By controlling the quantum wells in the active region, crosstalk between the devices can be eliminated. The multiple devices can also be made to crosstalk, and can be made coherent with respect to one another by mixing enough photons to phase lock the devices.

Abstract: A laser system including a controller for monitoring and controlling various functions of a laser assembly. The laser controller may include a wavelength tuning circuit for adjusting and locking the wavelength of the external cavity. To perform various monitoring and control functions, the controller may include circuitry for monitoring various parameters associated with operation of the laser, such as temperature indicating signals and/or signals from light detectors such as photodiodes.

Abstract: A distributed Bragg reflector (DBR) for a vertical cavity surface emitting laser (VCSEL) includes alternating layers of different semiconductor materials to improve thermal and electrical characteristics for the VCSEL. Use of particular materials reduces the thermal resistivity of the DBR and allows heat to dissipate quickly during operation of the VCSEL.

Abstract: The present invention provides a optical module comprising a semiconductor laser diode for outputting a laser beam; a first carrier on which the semiconductor laser diode is fixedly mounted; a photodiode for receiving a monitoring laser beam outputted from the back face of the semiconductor laser diode; a second carrier on which the photodiode is fixedly mounted; and a base on which the first and second carriers are fixedly mounted through soldering. At least one soldering sheet for soldering the first and second carriers on the base is fixedly pre-mounted on the base in place through spot welding.

Abstract: A cooling device for an optical amplifier or oscillator has Peltier elements enclosed in a housing with an optical crystal and extract heat from the optical crystal. The housing is sealed and can contain a desiccant for removing moisture and preventing particle deposition. Alternately, the housing can be evacuated with a vacuum to maintain a clean operating environment. The housing holds a Brewster window at a Brewster angle with an incident laser beam to permit passage of the laser beam. The housing also can be arranged on a platform providing liquid cooling.

Abstract: The present invention is a “Vertical Cavity Surface Emitting Laser” or “VCSEL” design, wherein the VCSEL device produces phase-conjugated distortion free (reversal of intracavity distortions like diffraction, divergence, and light scattering) and collimated (plane-parallel phase fronts) laser-light emissions. Moreover, through what is called intracavity degenerative four-wave mixing (called four-wave mixing because traditionally there are four frequencies of phase-matched laser light involved in the phase-conjugate process), that occurs within the nonlinear materials of the “Phase Conjugated Vertical Cavity Surface Emitting Laser” or “PCVCSEL” device's vertical-cavity.

Abstract: Graded semiconductor layers between GaN and AlGaN layers in a nitride based semiconductor laser structure reduce the threshold voltage of the laser structure by reducing the electric potential barrier at the interface between the GaN and AlGaN layers. The graded layers can be step graded, continuous graded or digital graded.

Abstract: A direct-drive modulator driver and an optical transponder including the driver are disclosed. The driver includes a transistor having a first terminal, a second terminal and an input terminal, where said first terminal is grounded. The driver further comprises of a laser diode having a p-terminal and an n-terminal, where said p-terminal is coupled to a power supply, and said n-terminal is coupled to the second terminal of the transistor. The driver further comprises of an input load coupled to the input terminal of the transistor.

Abstract: In a semiconductor pumping light source module according to the present invention, a fiber grating (FBG) is disposed, outside a ferrule, in an optical fiber that is inside a protective tube to define a cavity between the FBG and the semiconductor laser device. The FBG is disposed, outside the ferrule, in the optical fiber that is inside the protective tube inside a protective boot. The FBG is disposed on the optical fiber at a portion where no adhesive exists inside the protective tube. The semiconductor pumping light source module is used as a pumping light source of the optical amplifier. The semiconductor pumping light source is also used as the pumping light source of a Raman amplifier.

Abstract: An uncooled, through-hole configured laser module adapted to receive and transmit RF signals to a laser at bandwidths from direct current (DC) to about ten gigahertz. The laser module incorporates an option for two pin-out configurations. One pin-out configuration has one ground pin and one signal pin for operation at about one gigabit/second or one gigahertz. The second high performance pin-out uses two ground pins and one signal pin for operation up to about ten gigabit/second or ten gigahertz.

Abstract: Semiconductor lasers having a narrow bandwidth distributed Bragg reflector (DBR). The narrow bandwidth distributed Bragg reflector reflects photons over a narrow wavelength range for amplification within the laser cavity. Photons outside the narrow wavelength range are not reflected back into the laser cavity and are therefore not amplified. The narrow bandwidth distributed Bragg reflector can be formed of semiconductor materials or dielectric materials. The narrow bandwidth distributed Bragg reflector is included as part of folded cavity surface emitting lasers and edge emitting lasers. Photons within the narrow wavelength range of the narrow bandwidth distributed Bragg reflector reflects are of a relatively long wavelength to improve efficiency of communication over fiber optic cables.

Abstract: An LD/PD module having a main silicon substrate having a cavity, a transmitting portion having an LD and an LD driving IC which is directly mounted upon the main silicon substrate, and a receiving portion having a PD and an amplifier which is indirectly mounted upon the main silicon substrate via an auxiliary insulating substrate embedded in the cavity. The auxiliary insulating substrate suppresses current-induced crosstalk from the transmitting portion to the receiving portion.

Abstract: An array of VCSELs is made to operate coherently by coupling light to and from all elements with a common waveguide. The common waveguide can be fabricated on the wafer or separately, and allows enough optical power to mix between the individual lasers for phase-locking to occur.

Abstract: A surface emitting semiconductor laser of the present invention has a resonator including a pillar-form portion, and an emission portion having a convex lens form is formed on an upper surface of the pillar portion. The pillar-form portion has an embedded structure, with the periphery of the pillar-form portion embedded in an embedding layer. The embedding layer is formed of a substance having non-affinity with the material used to form the emission portion.

Abstract: A vertical-resonator-laser-diode and a method of manufacturing the same are disclosed. An active layer sequence for the production of laser-radiation is assembled between a first Bragg-reflector-layer-sequence and a second Bragg-reflector-layer-sequence. Each Bragg-reflector-layer-sequence has a plurality of mirror-pairs; the two Bragg-reflector-layer-sequences form a laser-resonator. The two Bragg-reflector-layer-sequences and the active layer-sequence are assembled between a first and a second electrical contact-layer. At least one of the two Bragg-reflector-layer-sequences is semitransparent for the laser-radiation. At least one light-absorbing layer is assembled with a given light-absorption either between the semitransparent Bragg-reflector-layer-sequence and the first electrical contact-layer, or on the light-outlet-side of the first electrical contact-layer.