Abstract: A semiconductor laser diode comprising a semiconductor substrate having an active layer with a pair of cavity facets opposed to each other on both ends of active layer as well as a first dielectric film of an oxide and a second dielectric film of an oxynitride successively stacked on one cavity facet has sufficient initial characteristics with a film structure having excellent heat radiability for allowing stable high-output lasing over a long period without reducing a catastrophic optical damage level on an emission end.

Abstract: A laser diode capable of operating at high temperature by preventing carrier overflow is provided. A laser diode includes an AlGaInP-based laminate configuration including at least a lower cladding layer, an active layer and an upper cladding layer in this order, wherein the AlGaInP-based laminate configuration receives a larger compressive stress than 2200 ppm from a stress source.

Abstract: A semiconductor laser diode including a substrate, and a first semiconductor layer, an active layer, a second semiconductor layer and an electrode sequentially formed on the substrate is provided. In the semiconductor laser diode, the second semiconductor layer has a ridge and the electrode is formed on the ridge of the second semiconductor layer at a width which is less than the width of the ridge.

Abstract: A reflection element 3 disposed in an optical waveguide element 2 returns a part of light to a semiconductor laser diode element 1 so that the semiconductor laser diode element 1 oscillates in a coherent collapse mode, and a semiconductor light amplifier 7 is optically coupled to the optical waveguide element 2, and amplifies an optical output from optical waveguide element 2, so as to provide a high-power fundamental-wave light source.

Abstract: A laser drive includes a variable output voltage source that can control an output voltage, a laser source connected to the variable output voltage source, a laser drive circuit that drives the laser source, and a monitoring controller that monitors an operating voltage of the laser drive circuit and controls the output of the variable output voltage source such that the monitored operating voltage becomes equal to a desired value.

Abstract: A projection and a raised portion are formed on an upper surface of a blue-violet semiconductor laser device. A projection and a raised portion are formed on a lower surface of a red semiconductor laser device. The height of the projection is smaller than the height of the raised portion, and the height of the projection is smaller than the height of the raised portion. The blue-violet semiconductor laser device and the red semiconductor laser device are joined to each other such that the projections are opposed to each other.

Abstract: Apparatus, methods, systems and devices for temperature independent or minimally temperature dependent narrow spectrum laser having an optimized output. The resonator includes at least one volume Bragg grating mirror that changes reflectance with temperature. The volume Bragg grating mirror in combination with a narrow spectrum laser optimizes the laser performance by being temperature tuned to the optimum reflectance. In an embodiment, the volume Bragg grating mirror has a temperature dependent reflectance that compensates for changes in the stimulated emission cross section of the gain medium and leads to a laser with output energy that is independent of temperature.

Abstract: A surface emitting semiconductor device comprises: a semiconductor region including an active layer; a first DBR having first layers and second layers; and a second DBR. The first and second layers are alternately arranged, and the first layers are made of dielectric material. The first DBR, semiconductor region and second DBR are sequentially arranged along a predetermined axis, and the semiconductor region is provided between the first DBR and the second DBR. The cross section of the first DBR is taken along a reference plane perpendicular to the predetermined axis. The distance between two points on an edge of the cross section takes a first value in a direction of an X-axis of a two-dimensional XY orthogonal coordinate system defined on the reference plane, and the distance between two points on the edge takes a second value in a direction of a Y-axis of the above coordinate system. The first value is different from the second value.

Abstract: A tunable laser has a multiple ring resonator comprising a plurality of ring resonators having respective ring-shaped waveguides and respective different optical path lengths, an input/output side optical waveguide coupled to the multiple ring resonator, an optical input/output device such as a laser diode coupled to the input/output side optical waveguide, a reflection side optical waveguide coupled to the multiple ring resonator, an optical reflector coupled to the reflection side optical waveguide for removing light at an unwanted wavelength and reflecting light at a required wavelength, and a wavelength varying mechanism for changing the resonant wavelength of the multiple ring resonator.

Abstract: A pressure of a laser gas in an enclosure (7) is detected by a gas pressure sensor (12), and a pressure comparison circuit (13) determines whether the thus-detected pressure is normal or anomalous. An electric current output from an inverter (10) that drives a blower (5) to cause a laser gas to flow back, is detected by a current detection circuit (9). A current comparison circuit (11) determines whether or not the output current is normal or anomalous. A result of a pressure comparison circuit (13) and a result of the current comparison circuit (11) are sent to an AND circuit (15) and performed AND processing. A result of the AND circuit (15), a result of the current detection circuit (9), and a result of the gas pressure sensor (12) are sent to a comparison operation section (17) in a controller (14). A determination is made as to whether or not the blower is anomalous.

Abstract: A gas laser oscillating unit having a gas junction part where gas flow may be stable, whereby a stable laser beam output and/or a laser beam that does not fluctuate very much may be achieved. The laser gas, flowing through first and second excitation parts, is introduced into the first and second tapered gas flow passages. After that, the two gas flows are mixed at or near the center point of a gas junction part and the mixed gas flows in a next flow passage. Then, one of the gas flows from the first excitation part is biased toward the ?X direction by a first biasing member arranged in the first gas flow passage, and the other gas flow from the second excitation part is biased toward the +X direction by a second biasing member arranged in the second gas flow passage.

Abstract: A laser module includes a semiconductor laser element and a feedback optical component forming an external cavity with the semiconductor laser element. Even if a ratio of a current threshold of the laser module changing according to a polarized state of returned light from the feedback optical component to a current threshold of the semiconductor laser element is in an arbitrary range within a predetermined range, a total value of a relative intensity noise occurring between a first frequency determined according to a cavity length of the external cavity and at least equal to or more than a frequency band of using a laser light and a second frequency calculated by multiplying the first frequency by a predetermined number is equal to or more than ?40 dB.

Abstract: A system for using a pulsed laser beam to process materials includes a selector for varying the pulse repetition rate of the laser beam. Also included is a control unit for identifying an optimal pulse repetition rate that is compatible with the required pulse energy level for processing the material. Variations in the pulse repetition rate can be made during a procedure pursuant to either pre-programmed instructions, or in response to closed loop feedback controls.

Abstract: A method of fabricating micro crystal fiber lasers and frequency-doubling crystal fibers is disclosed. The micro crystal fiber laser contains gain crystal fibers, frequency-doubling crystal fibers, and a semiconductor laser. The semiconductor laser provides a laser beam. The gain crystal fibers receive the laser beam and generate a base-frequency beam. The frequency-doubling crystal fibers have a polarization alternating period. The frequency-doubling crystal fibers are coupled to the gain crystal fibers to double the frequency of the base-frequency beam and provide a double-frequency beam with the required wavelength. In addition to providing a monochromic crystal fiber laser, the crystal fiber lasers in red, green, and blue light may be combined into an array, providing a color laser. The frequency-doubling crystal fiber can be formed using the LHPG method.

Abstract: The present invention is to provide a DFB-LD with a larger coupling efficiency between the grating and the active layer. The DFB-LD of the invention provides an n-type InP substrate, an n-type InP buffer layer, an AlGaInAs layer, a intermediate layer made of a material belonging to a group III-V compound semiconductor and containing phosphorous, and an active layer. The InP substrate and the InP buffer layer form a periodic undulation of the grating. Because of the AlGaInAs layer just provided on the InP buffer layer, the AlGaInAs layer and the intermediate layer can be thinned to get a flat top surface, which enhances the coupling efficiency between the grating and the active layer.

Abstract: A laser pumped tunable laser system is disclosed directed to achieving tunable outputs with high wall plug efficiencies. In particular, green laser pumped alexandrite lasers are discussed—both pulsed and CW—wherein the wall plug efficiencies of greater than 2% can be achieved using practical, commercially available pump lasers. In alternative approaches, frequency converted tunable radiation in the UV is achieved with high efficiency from compact, high beam quality devices.

Abstract: In a buried type structure including an active layer sandwiched between an n-type cladding layer and a p-type cladding layer and a current blocking layer having an opening for confining a current flowing to the active layer, a regrown layer made of a nitride semiconductor doped with a p-type impurity is formed on the current blocking layer so as to cover the opening of the current blocking layer, and a portion of the regrown layer buried in the opening disposed to be adjacent to a side face of the opening and having a given width W is changed to have the n-type conductivity. Accordingly, the opening of the current blocking layer is effectively narrowed, so as to realize a self-pulsation nitride semiconductor laser device.

Abstract: A laser system may include a first portion of laser host material adapted for amplification of laser radiation and a second portion of laser host material surrounding the first portion which may be adapted for suppression of ASE. The first portion of laser host material and the second portion of laser host material may be respectively doped at a different predetermined concentration of laser ions. A heat exchanger may be provided to dissipate heat from the first portion and the second portion.

Abstract: A semiconductor laser device includes a substrate having a first surface and a second surface opposite to the first surface, an active region formed on the second surface of the substrate, a cladding layer formed on the active region, and an insulation region formed in the cladding layer to form on the second surface of the substrate a first laser region having a first size and a second laser region having a second size different from the first size. The first laser region is used for generating a first optical spectrum having a first laser mode channel space. The second laser region is used for generating a second optical spectrum having a second laser mode channel space. A combination of the first optical spectrum and the second optical spectrum forms a single mode laser. Without any gratings, the semiconductor laser device is easy to be fabricated and has a low fabrication cost.

Abstract: Highly compact vertical cavity surface emitting laser structures formed by a lateral oxidation process are provided. Specifically, well-controlled oxidized regions bound and define the aperture of a laser structure in a current controlling oxidation layer, wherein the aperture comprises a conductive region in the oxidation layer. These oxidized regions are formed by the use of a pre-defined bounding pattern of cavities etched in the laser structure, which allow the embedded oxidation layer to be oxidized, and which results in a highly reproducible and manufacturable process.