Abstract: Output for a laser is greatly increased by altering the transmitivity of a superconductor layer which serves as one of the mirrors of the laser cavity. The superconductor layer is switched between a superconductive state, having reflectivity of one, and a non-superconductive state, having a reflectivity of less than one. When the mirror is in its superconducting state, output power is decreased and power in the cavity is increased, and when the mirror is in its non-superconducting state, output power of the laser is increased and power in the cavity decreases.

Abstract: A passively cooled solid-state laser system for producing high-output power is set forth. The system includes an optics bench assembly containing a laser head assembly which generates a high-power laser beam. A laser medium heat sink assembly is positioned in thermal communication with the laser medium for conductively dissipating waste heat and controlling the temperature of the laser medium. A diode array heat sink assembly is positioned in thermal communication with the laser diode array assembly for conductively dissipating waste heat and controlling the temperature of the laser diode array assembly. The heat sink assemblies include heat exchangers with extending surfaces in intimate contact with phase change material. When the laser system is operating, the phase change material transitions from solid to liquid phase.

Abstract: Optically pumped amplifiers, in particular solid-state amplifiers, comprise an amplification medium (1) and an optical pumping arrangement (5) via which the pumping radiation is coupled to the amplification medium (1), the pumping radiation being formed before coupling. The volume of the amplification medium is only partially pumped; the pumped volume of the amplification medium is approximately rectangular in cross-section and approximately perpendicular to the optical axis; and the ratio of the width to height of the rectangular cross-section is greater than 1:8.

Abstract: High-damage-threshold output couplers with reflectivities suitable for use in high-power Q-switched lasers can be constructed from two pieces of high-damage-threshold bulk material. The output couplers are formed by a thin fluid-filled gap between parallel faces of bulk materials. This forms a reflective Fabry-Perot etalon with a large bandwidth. By avoiding the use of dielectric coatings to form the output coupler, a common source of damage—optical damage to the dielectric coating—can be avoided, making it possible to produce higher-performance lasers.

Abstract: A cold-start wavelength-division-multiplexed (WDM) optical transmission system uses a synchronized etalon filter, DFB lasers and passive optical demultiplexers. The DFB lasers are tested under normal operating conditions and wavelength-selected for each channel. The wavelength selection is such that the laser operates within one half of the channel spacing from the standardized wavelength. For the cold-start operation, each laser is able to automatically find its operating wavelength without any prior knowledge of its operating conditions for the standardized wavelength. In addition, this system simultaneously adjusts the output power of each laser to a desired value.

Abstract: A highly heat conductive layer is combined with or placed in the vicinity of the optical waveguide region of active semiconductor components. The thermally conductive layer enhances the conduction of heat away from the active region, which is where the heat is generated in active semiconductor components. This layer is placed so close to the optical region that it must also function as a waveguide and causes the active region to be nearly the same temperature as the ambient or heat sink. However, the semiconductor material itself should be as temperature insensitive as possible and therefore the invention combines a highly thermally conductive dielectric layer with improved semiconductor materials to achieve an overall package that offers improved thermal performance. The highly thermally conductive layer serves two basic functions. First, it provides a lower index material than the semiconductor device so that certain kinds of optical waveguides may be formed, e.g., a ridge waveguide.

Abstract: A solid state laser includes a high absorption coefficient solid state gain medium such as Nd:YVO4 that is side pumped with a semiconductor laser diode array. The resonant cavity of the solid state laser is positioned so that the TEM00 mode is spaced from the face of the laser through which the laser is pumped by a distance sufficient to reduce diffraction losses but sufficiently near to allow coupling of pump light into the gain mode. The gain medium, the doping level of the gain medium, and the operating temperature of the pump laser are selected to efficiently couple pump light into the gain mode. The pump laser is positioned to side pump the gain medium without collimating or focusing optics between the pump laser and the face of the gain medium. A gap between the pump laser and the gain medium is empirically selected to match the angular extent of the pump laser output light to the height of the gain mode at the position of the gain mode fixed to optimize coupling and diffraction losses.

Abstract: An image forming apparatus is arranged to form an image with laser light emitted from a semiconductor laser source, and is constructed so as to protect the laser source from a breakdown, by regulating electric current flowing to the laser source no matter when an adjusting circuit for adjusting the light amount of the semiconductor laser source is apt to supply the electric current that could break the laser source, to the laser source.

Abstract: A wavelength conversion laser for generating sum frequency laser beam comprising a laser resonator, a solid-state laser active medium, a second harmonic generation wavelength conversion crystal and a sum frequency generation wavelength conversion crystal, wherein the length of the second harmonic generation wavelength conversion crystal along the optical axis is set to be shorter than that of the sum frequency generation wavelength conversion crystal.

Abstract: A plurality of fiber lasers or amplifiers which share a common pump source. Cost and efficiency improvement of waveguide fiber telecommunications systems are made possible by routing pump laser power through a 1×N coupler to supply pump light to desired combinations of optical fiber lasers or amplifiers. The design is readily adapted to the use of modules, for example laser modules which have a port for receiving pump light and a port for receiving a wavelength selecting module.

Abstract: Using a thin disk laser gain element with an undoped cap layer enables the scaling of lasers to extremely high average output power values. Ordinarily, the power scaling of such thin disk lasers is limited by the deleterious effects of amplified spontaneous emission. By using an undoped cap layer diffusion bonded to the thin disk, the onset of amplified spontaneous emission does not occur as readily as if no cap layer is used, and much larger transverse thin disks can be effectively used as laser gain elements. This invention can be used as a high average power laser for material processing applications as well as for weapon and air defense applications.

Abstract: A fiber laser uses a mechanism to prevent a thermally induced shift of the gain spectrum to a range that causes the laser to become destabilized when operated at a first signal wavelength. By establishing a nominal gain spectrum that is further from the undesired range than in a conventional laser, a gain spectrum shift does not reach the undesired wavelength range. This may be accomplished by decreasing the reflectivity of a resonant cavity of the laser, such as by angling the reflective end of the cavity. It may also be accomplished by increasing the population inversion of the laser. Using a pump energy reflector to prevent pump energy from exiting the inner cladding of a double-clad version of the laser the fiber may increase population inversion. The fiber length may also be shortened or the diameter of the inner cladding reduced to increase the population inversion before a laser output is achieved.

Abstract: The output frequency of a semiconductor laser beam is stabilized using a grating or another optical device which has an interaction with the beam whose parameters are sensitive to the beam frequency. The grating (130) generates positive and negative first order diffracted beams (132, 134), whose angle of diffraction is sensitive to the beam frequency, and is detected by split photodetectors AB, CD respectively. In the event of a change in beam frequency the outputs from the photodetectors AB, CD will vary to provide an error signal for the laser frequency. This error signal is insensitive to variations in angular alignment between the beam and the diffraction grating. This is because variations in frequency and variations in angular alignment cause different changes in the outputs of the photodetectors AB, CD.

Abstract: A passively mode-locked short pulse laser arrangement (1) comprising a laser resonator to which a pump beam (3) is supplied, a laser crystal (4), in particular a titanium-sapphire-(Ti:S-) laser crystal, and laser mirrors (M1 to M7), the laser crystal (4), which is subjected to a thermal load on account of the beam focussing, being mounted on a cooling body (10) provided for the removal of heat, which cooling body includes a bore (13) for the passage of the laser beam (3; 8), and on which a, particularly platelet-shaped, crystal mount (11) of a material with good heat conducting properties, preferably of copper, is provided for an improved removal of heat, the laser crystal (4) being held in an opening (14) of this crystal mount (11) by lateral abutment on oppositely arranged walls (15, 16) of the opening (14) of the crystal mount (11), the opening (14) in the crystal mount (11) being in alignment with the bore (13) in the cooling body (10).

Abstract: Diode lasers are fabricated whose performance is essentially unchanged over designed temperature and bias ranges. The threshold current (Ith) and the external efficiency (&eegr;ext) of the diode lasers are unchanged over a range of specified temperatures.

Abstract: Optical reflector for receiving an input beam and transmitting a retro-reflected reciprocal output beam. The optical reflector includes a beam splitter for splitting the input beam into first and second secondary beams. The first and second secondary beams being parallel to one another. A reflecting system is also included for redirecting the first and second secondary beams toward the beam splitter. The reflecting system including a total reflector. The beam splitter and the reflecting system are self-aligned.

Abstract: The gas laser oscillator of the invention comprises a discharge tube, a pair of electrodes disposed at both ends thereof, a direct-current high voltage power source for applying a direct-current high voltage in pulse form to the pair of electrodes, an output control device for controlling the direct-current high voltage power source, a fully reflective mirror provided at one end of the outside of the pair of electrodes, a partially reflective mirror disposed at the other end of the outside of the pair of electrodes, and an absorber disposed outside of the partially reflective mirror. In thus constituted gas laser oscillator, the output control device controls to apply a same direct-current voltage as during processing between the pair of electrodes also on standby while the absorber is closed.

Abstract: In the pattern of a selective growth mask for directly forming an active layer, open stripes for growing recombination layers to be inserted into a current blocking are formed in addition to an open stripe for growing the active layer. By this mask pattern, the position and band gap of the recombination layers are controlled. Whereby, at an arbitrary position in the vicinity of the active layer, recombination layers having an arbitrary band gap can be batch formed together with the active layer. Thus, a semiconductor laser element with an excellent high-temperature high-output characteristic can be fabricated with good uniformity and reproducibility.

Abstract: An edge-emitting laser having an edge-emitting output and a surface-emitting output. The edge-emitting laser has a resonator having a high order grating, preferably a second order grating capable of producing an edge-emitting component and a surface-emitting component. A waveguide is also located in the resonator and a cap layer is located above the waveguide and grating. The cavity is tested by taking measurements from the surface-emitting component eliminating the need for taking measurements from the edge-emitting component which is time consuming and expensive.

Abstract: A semiconductor laser apparatus comprises a semiconductor laser, a photodetector, first and second variable gain units, a controllable amplifying unit a driving unit, and a compensation unit. A control signal is supplied to one of input terminals of each of the first and second variable gain units and an output signal of the photodetector is negative-fed back to the other of the input terminals of each of the first and second variable gain units. A varied gain of an error between the control signal and the output signal is output independently of each of the first and second variable gain units. The controllable amplifying unit amplifies the error signal from the first variable gain unit with desired frequency characteristics. The driving unit includes a plurality of driving elements connected in parallel and supplies a driving current to the semiconductor laser in accordance with a drive control signal from the controllable amplifying unit.