Abstract: Providing a surface-emitting laser light source capable of generating a linearly polarized laser light having a single-lobed beam profile that takes the largest intensity value in its central area. A two-dimensional photonic crystal consisting of a plate member with holes arranged in a square lattice pattern is provided on one side of an active layer. The holes are designed so that its plane shape on the emission side (plane “B”) is smaller than that on the active layer side (plane “C”). The center of gravity of the shape on plane “B” is displaced from that of the shape on plane “C” in the in-plane direction. This design lowers the degree of the in-plane symmetry of the two-dimensional photonic crystal, so that a linearly polarized laser light having a single lobe is obtained.

Abstract: Solid-state laser(s) pumped by incoherent, monochromatic light from sources such as LED arrays and integrating technologies such as high power LED arrays and solid-state laser materials in conjunction with efficient and uniform absorption of pumping energies through a diffusing pump chamber. The resulting laser(s) are compact, robust, low-cost, and able to produce high power output for practical applications. It may efficiently operate over wide temperature and performance ranges, at CW or pulse modes, even with ultra short pulse width and/or extremely high repetition rates. Our inventive structure(s) is/are highly flexible and applicable to a large group of lasing media including those with very short upper state life times. Advantageously, they may be applied to a plethora of laser systems at wavelengths that have important applications and unavailable to other direct pumping technologies.

Abstract: A quantum nanostructure semiconductor laser includes a strip-shaped ridge with a plurality of V-grooves formed on a compound semiconductor substrate in the direction of laser beam emission, with the V-grooves arrayed in parallel and with each V-groove extending orthogonally to the direction of laser beam emission. On the ridge, an optical waveguide is provided that includes a lower cladding layer, a plurality of quantum wires, and an upper cladding layer. The quantum wires are formed to a finite length corresponding to the stripe width of the laser beam, and are each located at a position corresponding to a V-groove location. The optical waveguide is trapezoidal in shape. The quantum wires do not project out beyond the width of the ridge, but the ends of the wires are converged and closed off with the upper and lower cladding layers toward higher index crystalline planes.

Abstract: A laser driver circuit driving a laser diode to generate an optical output corresponding to an input data, and controlling the optical output based on an output current from a photodiode that detects the optical output. The output current is converted into a voltage signal, whose amplitude is detected after filtering the voltage signal by a low-pass filter. A reference signal corresponding to the input data is generated, and its amplitude is detected. A modulator for generating a modulation current regulates the amplitude of the modulation current according to the difference between the two detected amplitudes.

Abstract: A compact mid-IR laser device utilizes a quantum cascade laser to provide mid-IR frequencies suitable for use in molecular detection by signature absorption spectra. The compact nature of the device is obtained owing to an efficient heat transfer structure, the use of a small diameter aspheric lens and a monolithic assembly structure to hold the optical elements in a fixed position relative to one another. The compact housing size may be approximately 20 cm×20 cm×20 cm or less. Efficient heat transfer is achieved using a thermoelectric cooler TEC combined with a high thermal conductivity heat spreader onto which the quantum cascade laser is thermally coupled.

Abstract: A control method for a laser diode is conducted such that optical output and OMA (optical modulation amplitude) or extinction ratio of the laser diode are controlled while modulating the optical output of the laser diode by applying a bias current and a modulation current to the laser diode. The method has: a first step of measuring the optical output of the laser diode; a second step of measuring a slope efficiency or a corresponding value of the slope efficiency while conducting APC (automatic power control) to adjust the bias current such that the optical output coincides with a predetermined value; and a third step of adjusting the modulation current by AAC (automatic amplitude control) according to the slope efficiency or the corresponding value of the slope efficiency such that the OMA or extinction ratio coincides with a predetermined value.

Abstract: A narrow linewidth semiconductor laser device has a semiconductor laser and a low noise current source operatively connected to the laser with the current source being adapted to prevent degradation of the laser's frequency noise spectrum. An optical frequency discriminator provides an error signal representative of the laser's optical frequency and a control circuit has a feedback network that provides a frequency feedback signal that is adapted to the frequency noise spectrum of the frequency discriminator and to the laser's frequency noise spectrum and tuning response. The control circuit also has a sequencer to automatically enable frequency locking of the laser on the frequency reference of the optical frequency discriminator. An enclosure encloses the frequency discriminator to isolate the frequency discriminator from external perturbations.

Abstract: A line narrowed gas discharge laser system and method of operation are disclosed which may comprise: an oscillator cavity; a laser chamber comprising a chamber housing containing a lasing medium gas; at least one peaking capacitor electrically connected to the chamber housing and to a first one of a pair of electrodes; a second one of the pair of electrodes connected to an opposite terminal of the at least one peaking capacitor; a current return path connected to the chamber housing; the one terminal, the first one of the electrodes, the lasing medium gas, the second one of the electrodes, the current return path and the second terminal forming a head current inductive loop having an inductance unique to the particular head current inductive loop; a spectral quality tuning mechanism comprising a mechanism for changing the particular head current inductive loop inductance value for the particular head current inductance loop.

Abstract: Light emitted from a wide stripe semiconductor laser with increased output and efficiency is passed through a mode converter and a wavelength selecting filter, then fed back to the active layer of the semiconductor laser, which fixes the oscillation mode of the semiconductor laser to single mode, making lateral-mode control possible.

Abstract: An optical device includes a chip containing a Vertical Cavity Surface Emitting Laser (VCSEL) active region that produces a laser beam on a first axis. The VCSEL can further include a post having a central axis offset a distance from the first axis. A lens can be mounted on the post such that it bends the laser beam away from the first axis. Alternately, the chip can include multiple VCSEL active regions each of which produces a laser beam on a different axis. The chip can include a post having a central axis offset from the laser beam axes. A lens can be mounted on the post such that the lens bends the laser beams away from the central axis.

Abstract: A laser diode driver circuit can comprise fast loop portion and a closed-loop portion. The closed-loop driver portion can provide a part of the current for a laser diode. The closed-loop drive portion output can be independent of a photodetector. The fast-loop driver portion can provide a second part of the current for the laser diode. The fast-loop driver portion can use the output of the photodiode to determine the output of the fast-loop driver portion.

Abstract: A laser device applied to a light source of laser scanning units (LSU) including a laser diode disposed on an accommodation hole of a flange. A collimator lens is arranged on one end of an inner tube part of a holder while the other end of the inner tube part faces the laser diode. The laser beam passes through the inner tube part of the holder and the collimator lens, then projects out. A lug extends radially from outer surface of the holder and a plurality of axial guide slots are disposed on the lug. A plurality of guide pins corresponding to the guide slots are arranged on the flange. An adhesive is located between the guide pins and the guide slots and spaced apart from the collimator lens.

Abstract: An integrated light emitting semiconductor device having integrated feedback for wavelength locking comprises a semiconductor substrate including a waveguide region having a gain section having a gain media therein, and an out-coupling perturbation integrated with the device disposed proximate to the waveguide. A total internal reflection (TIR) structure for providing optical feedback is integrated with the device and disposed in a spaced apart relation relative to the out-coupling perturbation. At least one of the out-coupling perturbation and the TIR structure include a grating or prism to provide dispersion to send different wavelengths of light in different directions. The out-coupling perturbation is preferably a grating that has a grating period that is small enough to allow for only the +1 diffracted order to propagate.

Abstract: Laser apparatus and methods involving multiple amplified outputs are disclosed. A laser apparatus may include a master oscillator, a beam splitter coupled to the master oscillator, and two or more output heads optically coupled to the beam splitter. The beam splitter divides a signal from the master oscillator into two or more sub-signals. Each output head receives one of the two or more sub-signals. Each output head includes coupling optics optically coupled to the beam splitter. An optical power amplifier is optically coupled between the beam splitter and the coupling optics. Optical outputs from the two or more output heads do not spatially overlap at a target. The master oscillator signal may be pulsed so that optical outputs of the output heads are pulsed and substantially synchronous with each other.

Abstract: According to the present invention, a first p-side electrode 7A made of metal which is provided with regularly arranged holes 10 having a diameter smaller than a laser oscillation wavelength and a second p-side electrode 7B arranged around the periphery of the first p-type electrode 7A are used as a p-side mirror of a surface-emitting laser. Light in a resonator formed of a p-side electrode 7 and an n-type mirror 2 is first converted to a surface plasmon and then reconverted to the light by the p-side electrode 7A, and then emitted outside the resonator.

Abstract: An improved tube solid-state laser (SSL) is provided utilizing diode pumping, microchannel cooling, optics, and/or new coating and bonding processes. In one example, an amplifier module for the SSL includes a tube of laser gain material, a first substrate and a second substrate including microchannels adjacent an interior and exterior surface of the tube, respectively, and a plurality of diode bars arranged exterior to the second substrate. Advantageously, thermal lensing effects, birefringence, bifocussing, and alignment problems associated with typical tube SSLs are eliminated or reduced while providing high beam quality and high average power levels.

Abstract: An external cavity laser has a mirror-based resonant tunable filter, such as a Fabry Perot tunable filter or Gires-Tournois interferometer tuning element, with the tunable filter being preferably used as a laser cavity mirror. A mirror-based resonant tunable filter is selected in which the spectral response in reflection has an angular dependence. A tilt scheme is used whereby by selecting an appropriate angle between the filter's nominal optical axis and the cavity optical axis, a narrowband peak spectral reflection is provided to the laser cavity. This tunable narrowband spectral reflection from the filter is used to lock and tune the laser output wavelength.

Abstract: A device includes a multiple quantum well with potential barriers and quantum wells, and an electric field element for applying an electric field thereto. The multiple quantum well includes at least two regions A and a region B disposed therebetween. The region A includes a plurality of energy levels, and a carrier is transported from a specific energy level i to a specific energy level f in the region A through one of the potential barriers by photon-assisted tunneling. The region B includes a plurality of energy levels, and an energy relaxation is performed with a relaxation time shorter than a transit time of the carrier in the region A from a specific energy level e to a specific energy level g in the region B. When an electric field is applied, electric current flows through the multiple quantum well and light is emitted or absorbed in the region A.

Abstract: An optical amplifier including: a photonic gain clement; and, a transistor electromagnetically coupled to the gain element to inject current into the gain element responsively to the internal optical intensity of the gain element. The coupling of the transistor and the photonic gain element is such that as the optical intensity within the photonic gain element increases, the current injected by the transistor increases, thereby preventing filamentation in the photonic gain element.

Abstract: A semiconductor optoelectronic device includes at least one cavity and one multilayered interference reflector. The cavity is designed preferably to possess properties of an antiwaveguiding cavity, where no optical modes propagate in the lateral plane. The existing optical modes are the modes propagating in the vertical direction or in a direction tilted to the vertical direction at an angle smaller than the angle of the total internal reflection at the semiconductor/air interface. This design reduces the influence of parasitic optical modes and improves characteristics of optoelectronic devices including vertical cavity surface emitting lasers, tilted cavity lasers emitting through the top surface or the substrate, vertical or tilted cavity resonant photodetectors, vertical or tilted cavity resonant optical amplifiers, and light-emitting diodes.