Abstract: A semiconductor diode laser having a broad vertical waveguide and a broad lateral waveguide is disclosed emitting laser-light in a single vertical mode and a single lateral mode narrow beam. The vertical waveguide comprises a coupled cavity structure, wherein light, generated in the active medium placed in the first cavity leaks into the second cavity and returns back. Phase matching conditions govern the selection of a single vertical mode. A multi-stripe lateral waveguide comprises preferably a lateral photonic band crystal with a lateral optical defect created by selected pumping of multistripes. This approach allows the selection of a single lateral mode having a higher optical confinement factor and/or a lower absorption loss and/or a lower leakage loss compared to the rest lateral optical modes. This enables a single lateral mode lasing from a broad area field coupled laser array.

Abstract: A semiconductor laser device includes: an n-type cladding layer; a p-type cladding layer; and an optical waveguide portion disposed between the n-type and p-type cladding layers and including spaced-apart active layers. The optical waveguide portion permits lasing in a crystal growth direction of the active layers in at least three modes, including the fundamental mode and two higher order modes. The number of active layers is equal to or greater than the number of extreme points of the electric field of a particular one of the higher order modes. At least one of the active layers is disposed near each extreme point of the electric field of the particular higher order mode, within the optical waveguide portion.

Abstract: A group III nitride semiconductor laser is provided that has a good optical confinement property and includes an InGaN well layer having good crystal quality. An active layer 19 is provided between a first optical guiding layer 21 and a second optical guiding layer 23. The active layer 19 can include well layers 27a, 27b, and 27c and further includes at least one first barrier layer 29a provided between the well layers. The first and second optical guiding layers 21 and 23 respectively include first and second InGaN regions 21a and 23a smaller than the band gap E29 of the first barrier layer 29a, and hence the average refractive index nGUIDE of the first and second optical guiding layers 21 and 23 can be made larger than the refractive index n29 of the first barrier layer 29a. Thus, good optical confinement is achieved. The band gap E29 of the first barrier layer 29a is larger than the band gaps E21 and E23 of the first and second InGaN regions 21a and 23a.

Abstract: A surface emitting semiconductor laser includes a substrate, a lower reflective mirror formed on the substrate, an active layer formed on the lower reflective mirror, an upper reflective mirror formed on the active layer, an optical mode controlling layer formed between the lower reflective mirror and the upper reflective mirror, and a current confining layer formed between the lower reflective mirror and the upper reflective mirror. The active layer emits light. The upper reflective mirror forms a resonator between the lower reflective mirror and the upper reflective mirror. In the optical mode controlling layer, an opening is formed for selectively absorbing or reflecting off light that is emitted in the active layer. The optical mode controlling layer optically controls mode of laser light. The current confining layer confines current that is applied during driving.

Abstract: A heat sink has a first flat plate, a partition plate, and a second flat plate. The first flat plate has an upper surface in which a first recess is formed. The second flat plate has a lower surface in which a second recess is formed, and an upper surface on which a semiconductor laser element is mounted. These recesses form a part of a refrigerant channel. The partition plate has a lower surface covering the first recess, an upper surface covering the second recess, and at least one through hole having the first recess communicated with the second recess. The first flat plate and the second flat plate both have a first coefficient of thermal expansion. The partition plate has a second coefficient of thermal expansion lower than the first coefficient of thermal expansion.

Abstract: A laser apparatus with all optical-fiber includes a plurality of pumping light sources in different wave bands and an optical-fiber laser system. The optical-fiber laser system includes an optical fiber at least doped with erbium (Er) element and doped with or not doped with ytterbium (Yb) element according to a need. The optical-fiber laser system outputs a laser light through the pumping light source.

Abstract: A laser diode array having a plurality of diode bars bonded by a hard solder to expansion matched spacers and mounted on a gas or liquid cooled heatsink. The spacers are formed of a material such as copper/diamond composite material having a thermal expansion that closely matches that of the laser bars.

Abstract: This invention relates to a self-induced transparency mode-locked quantum cascade laser having an active section comprising a plurality of quantum well layers deposited in alternating layers on a plurality of quantum barrier layers and form a sequence of alternating gain and absorbing periods, said alternating gain and absorbing periods interleaved along the growth axis of the active section.

Abstract: A temperature compensating method of laser power in an optical disk storage apparatus is disclosed whereby temperature is compensated so that laser power outputted by a laser diode can be constantly outputted regardless of temperature changes. According to the present invention, a current temperature for operating the laser diode is detected and a linear Equation of a laser power voltage outputted by the laser diode in response to an input current is obtained from the detected current temperature. An input current corresponding to a laser power voltage desired by the obtained linear Equation is calculated and is supplied to the laser diode. Therefore, a laser power desired by the laser diode can be outputted regardless of the temperature changes, thereby enabling to establish an accurate input current.

Abstract: The basic gain medium enclosure for laser devices comprises two parallel lateral mirrors which geometrically define the extent of the gain medium enclosure and which allow the formation of lateral stationary sinusoidal waves.

Abstract: A method of manufacturing a nitride semiconductor device includes the steps of: forming a division guide groove by applying a laser beam having a wavelength and energy density causing multiphoton absorption to a surface of a substrate having a group III nitride semiconductor layer grown on a major surface thereof; removing deposits from the surface of the substrate by applying a laser beam having the wavelength to the surface of the substrate at energy density causing substantially no multiphoton absorption on the substrate; and dividing the substrate along the division guide groove.

Abstract: A polarization-maintaining figure eight (PMFE) fiber laser is configured to generate ultrashort (femtosecond) output pulses by intentionally inserting asymmetry (in the form of a phase bias) into the bi-directional loop of the fiber laser. The introduction of asymmetry (via an asymmetric coupler, splice, attenuator, fiber bend, multiple amplifying sections, or the like) allows for an accumulation of phase difference within the bi-directional loop sufficient to create modelocking and generate ultrashort output pulses.

Abstract: A method to stabilize the repetition rate in a passive harmonic mode-locked fiber laser employing semiconductor saturable absorbers. The pulse organization is accomplished by electrically modulating the amplifier pump source that in turn optically modulates the saturable loss of semiconductor absorber. Due to an efficient modulation mechanism of the cavity loss, the method can be used to generate an actively mode-lock pulse train.

Abstract: When configuring a surface emitting laser by a semiconductor material not capable of largely extracting a refractive-index difference, the surface emitting laser using a photonic crystal capable of forming a waveguide is provided.

Abstract: Laser diode driver architectures are disclosed. Some example current drivers are described, including a current channel to provide an output current. The current channel includes a current mirror with emitter degeneration, a startup transistor coupled to the current mirror to generate a DC bias on the current mirror, a beta helper circuit coupled to the current mirror and the startup transistor, to maintain the DC bias on the current mirror, and a cutoff transistor coupled to an emitter terminal of a current mirror transistor and to a reference voltage, to selectively couple the emitter terminal to the reference voltage to conduct the pre-determined output current. The example current drivers also include an output stage coupled to the output of the current mirror and to an output device, wherein the output stage provides a current gain in response to the cutoff transistor coupling the emitter terminal to the reference voltage.

Abstract: A polymer film laser is provided that comprises a plurality of extruded polymer layers. The plurality of extruded polymer layers comprises a plurality of alternating dielectric layers of a first polymer material having a first refractive index and a second polymer material having second refractive index different than the first refractive index.

Abstract: The laser diode comprising crystalline substrate (1) where set of subsequent n-type layers, set of optically active layers (5) and set of p-type layers is deposited. The set of n-type layers comprise at least one buffer layer (2), bottom n-type cladding layer (3) and n-type bottom waveguide layer. The set of p-type layers comprise at least p-type upper waveguide, which comprises electron blocking layer, upper p-type cladding layer (7) and p-type contact layer (8). The electron blocking layer comprises Inx, AlyGa1-x-y, N alloy doped with magnesium where 1?x>0.001 a 1?y 0. The way of making this invention is based on the epitaxial deposition of subsequent set of the n-type layers (2, 3, 4), set of optically active layers (5) and set of p-type layers (6, 7, 8) where the p-type waveguide layer (6) and p-type contact layer (7) is deposited with presence of indium in plasma assisted molecular beam epitaxy method.

Abstract: An objective of the present invention is to provide a surface emitting laser capable of selectively generating a laser oscillation in the fundamental mode and thereby emitting a single-wavelength laser light. In a surface emitting laser including an active layer and a two-dimensional photonic crystal provided on one side of the active layer, a reflector 45 or 46 is provided at least at a portion of the circumference of the two-dimensional photonic crystal. The reflector has a reflectance distribution in which the reflectance has a maximum value at a position where the amplitude envelope of the fundamental mode of an internal resonance light created within the two-dimensional photonic crystal. This design strengthens the fundamental mode while suppressing the second mode, thus enabling the laser oscillation in the fundamental mode to be selectively obtained, so that a single-wavelength laser light can be emitted.

Abstract: The invention provides a cascade Raman laser including a pumping laser light source that generates pumping light, a cascade Raman resonator having an input-side optical reflector that receives the pumping light and selectively reflects light of each wavelength corresponding to a n-th Stokes ray (n is an integer more than 1) of Raman scattering to the pumping light, a Raman optical fiber that is connected to the input-side optical reflector and generates Raman scattering light at least by the pumping light and an output-side optical reflector that is connected to the Raman optical fiber and selectively reflects light of each wavelength corresponding to the n-th Stokes ray and a blocking device interposed between the pumping laser light source and the cascade Raman resonator and blocks the first Stokes ray generated within the cascade Raman resonator from entering the pumping laser light source side.

Abstract: In one embodiment, a photo-darkening resistant optical fiber includes a waveguide having a numerical aperture less than 0.15. The waveguide includes a core having a refractive index n1 and a pedestal having a refractive index n2, and wherein the fiber includes a first cladding having a refractive index n3 surrounding the pedestal, wherein n1 is greater than n2, n2 is greater than n3. The core includes silica, a concentration of alumina of between approximately 0.3 to 0.8 mole percent, a concentration of phosphate of substantially 15 mole percent, a concentration of ytterbium substantially in the range 20000 to 45000 ppm. The pedestal can include silica, phosphate and germania. The core can have substantially zero thulium dopant.