Abstract: In a wavelength conversion laser device, a laser light source emits first wavelength light. A non-linear optical crystal converts the first wavelength light into second wavelength light. A rotational driver rotates the non-linear optical crystal so as to alter an incidence angle of the first wavelength light with respect to the non-linear optical crystal. A rotational driving controller detects a portion of an output of the second wavelength light, generates a rotational control signal of the non-linear optical crystal in accordance with a change in the output, and transmits the rotational control signal to the rotational driver. A beam location maintaining mirror retroreflects the second wavelength light, outputted from the non-linear optical crystal, along a substantially same path as that of the first wavelength light. Also, an output beam distributor guides the retroreflected second wavelength light in a desired output direction.

Abstract: A wavelength conversion laser apparatus including: a laser light source emitting primary wavelength light; a non-linear optical crystal including: a light waveguide region having a first refractivity, the light waveguide region receiving the primary wavelength light to output as secondary wavelength light; and a clad region adjacent to the light waveguide region, the clad region having a second refractivity lower than the first refractivity, wherein at least the light waveguide region has a periodically domain-inverted structure formed such that a domain-inverted period varies in a direction perpendicular to an incident axis of the primary wavelength light; and a mover moving the non-linear optical crystal to change the domain-inverted period on a path where the primary wavelength light incident on the light waveguide region passes.

Abstract: A wavelength conversion laser device and a nonlinear optical crystal used in the same. The wavelength conversion laser device includes a laser light source for emitting a predetermined wavelength beam, and a laser medium for exciting the predetermined wavelength beam from the laser light source into a fundamental beam. The wavelength conversion laser device further includes a nonlinear optical crystal composed of a KTiOPO4 (KTP) crystal having b-c crystal plane as an incident surface of the fundamental beam to provide type II phase matching conditions. The KTP crystal converts the fundamental wavelength beam into a second harmonic generation beam.

Abstract: In a wavelength conversion laser device, a laser light source emits first wavelength light. A non-linear optical crystal converts the first wavelength light into second wavelength light. A rotational driver rotates the non-linear optical crystal so as to alter an incidence angle of the first wavelength light with respect to the non-linear optical crystal. A rotational driving controller detects a portion of an output of the second wavelength light, generates a rotational control signal of the non-linear optical crystal in accordance with a change in the output, and transmits the rotational control signal to the rotational driver. A beam location maintaining mirror retroreflects the second wavelength light, outputted from the non-linear optical crystal, along a substantially same path as that of the first wavelength light. Also, an output beam distributor guides the retroreflected second wavelength light in a desired output direction.

Abstract: A wavelength conversion laser device includes a laser light source for emitting a first wavelength light, a nonlinear optical crystal for converting the first wavelength light into a second wavelength light, and a nonlinear optical crystal rotator for rotating the nonlinear optical crystal so as to change an incident angle of the first wavelength light into the nonlinear optical crystal. The device also includes a nonlinear optical crystal rotation driving controller for controlling a rotation amount of the rotator in accordance with an output change of the second wavelength light so that the nonlinear optical crystal has phase matching with the first wavelength light. The device further includes a light exit position adjustor for compensating an exit position change of the second wavelength light in accordance with the incident angle change of the first wavelength light so that the second wavelength light is outputted in a predetermined exit position.

Abstract: an engine includes: a cylinder block; and a piston ring, in which the cylinder block has a cylinder liner portion formed of an aluminum-based composite reinforced by a ceramic containing at least either of a silicon carbide and an alumina, and in which the piston ring is coated with a nitride film (20) including a vanadium nitride layer (21) exposed on an outer circumferential sliding surface (17).

Abstract: A piston ring 1 for internal combustion engines comprises a hard film 2 formed on at least an outer circumferential sliding surface of the piston ring 1. The hard film 2 includes chromium, nitrogen and silicon as structural elements and the same crystal structure as CrN, and is composed of a crystal phase where silicon is contained in a solid solution state in a crystal lattice at an atomic ratio between 1 and 9.5 percent. The hard film may be the following film. Namely, a hard film is composed of a mixed phase of a crystal phase and an amorphous phase; the crystal phase includes chromium, nitrogen and silicon as structural elements and the same crystal structure as CrN and moreover includes silicon contained in a solid solution state in a crystal lattice; the amorphous phase includes silicon, nitrogen and chromium as structural elements; the ratio of the amorphous phase in the hard film is 4.5 percent or less; and the silicon content in the hard film is between 1 and 9.5 percent at an atomic ratio.

Abstract: The invention provides an optical fiber laser apparatus. In the invention, an excitation light source outputs light of a given wavelength. A first optical fiber generates light of a plurality of wavelengths including light of a first wavelength by up-conversion from the output light. Also, a first resonator includes first and second mirrors provided on both ends of the first optical fiber, respectively. The first resonator selects the first wavelength light to output via the second mirror. Further, a second optical fiber amplifies an output of the first wavelength light incident from the first resonator. In addition, the first and second mirrors have higher reflexivity for the first wavelength light than the second wavelength light having higher gain per length of the optical fiber. The first fiber has a length set such that the first wavelength light oscillates preferentially over the second wavelength light.

Abstract: The invention provides an up-conversion optical fiber laser apparatus with an external resonator structure. In the invention, a laser element outputs light of a first wavelength to excite an up-conversion optical fiber doped with rare earth ions used for converting the first wavelength light into a second wavelength light. An output mirror is disposed at an output end of the optical fiber, and cooperates with a high reflective layer of the laser element to operate as a resonator for the first wavelength light. An input mirror is disposed at an input end of the optical fiber and cooperates with the output mirror to operate as a resonator for the second wavelength. A polarization mode controller converts light incident from the optical fiber into light of eigen-polarization wave for the laser element and outputs the converted light to the laser element.

Abstract: The invention provides an optical fiber laser apparatus. In the invention, an excitation light source outputs light of a given wavelength. A first optical fiber generates light of a plurality of wavelengths including light of a first wavelength by up-conversion from the output light. Also, a first resonator includes first and second mirrors provided on both ends of the first optical fiber, respectively. The first resonator selects the first wavelength light to output via the second mirror. Further, a second optical fiber amplifies an output of the first wavelength light incident from the first resonator. In addition, the first and second mirrors have higher reflexivity for the first wavelength light than the second wavelength light having higher gain per length of the optical fiber. The first fiber has a length set such that the first wavelength light oscillates preferentially over the second wavelength light.

Abstract: The present invention relates to a backlight apparatus for a Liquid Crystal Display. The backlight apparatus includes a main light source for generating white light and a monochromatic light source for generating monochromatic light to compensate the color temperature of the white light. The backlight further includes a light mixing region for mixing the white light with the monochromatic light to form mixed light with compensated color temperature and a reflection plate disposed underneath the light mixing region. The invention provides the monochromatic light source in addition to the fluorescent lamp, widening the color expression range and effectively adjusting the color temperature, thereby enabling natural color expression.

Abstract: A hingeless mirror device includes a conductor portion having electrical-conductivity for forming a closed spacing, a planar conductor mirror stored in the closed spacing, a plurality of electrodes mutually insulated and disposed on a conductor via an insulative substrate, a transparent electrode provided above an opening of the conductor, a power supply section which supplies voltages to the conductor and transparent electrode, and a control section which supplies control voltages to the plurality of electrodes, and which causes the closed spacing to generate an electrostatic force, thereby controlling a tilt angle of the conductor mirror. According to the hingeless mirror device, since the conductor portion is stabilized in potential, an unnecessary electrostatic force and the like do not occur, thereby enabling the control to be securely performed.

Abstract: Light from a first excitation light source is incident on one facet of a first optical fiber. A core is doped with a first rare earth substance. A resonant section induces light resonance in the core to generate resonant light, thereby providing selected light at the other facet of the first optical fiber. An optical multi/demultiplexer reflects the light of the selected wavelength in a direction different from that of the first optical fiber. A second excitation light source supplies light to the resonant section of the first optical fiber via the optical multi/demultiplexer and the other facet of the first optical fiber. A second optical fiber guides the light of the selected wavelength from the optical multi/demultiplexer to an exterior.

Abstract: A fiber laser apparatus, an image display apparatus and an excitation method for an up-conversion fiber laser apparatus are disclosed. A polarizer and a high-reflection mirror for retrieving an up-conversion laser output are interposed between an exciting laser for emitting an exciting laser beam and a rare-earth-doped fiber. That portion of the exciting laser beam output from the output side of the rare-earth-doped fiber which has a polarized wave directed at right angles to the polarized wave incident on the rare-earth-doped fiber is returned into the rare-earth-doped fiber. The exciting laser beam having the other polarized wave is output in a direction different from the direction of the exciting laser.

Abstract: Rays of light emitted from the semiconductor laser are converted into parallel rays of light by cylindrical lenses. Then, the light passed through the cylindrical lenses is caused to enter an optical fiber changed continuously from a specific position in the middle toward an incidence end part in such a manner that the core shape at the incidence end part becomes elliptic, with the cross-sectional area remaining unchanged.

Abstract: A fiber laser apparatus comprises a plurality of semiconductor lasers, and an optical fiber which beams emitted from the plurality of semiconductor lasers are caused to enter. The plurality of semiconductor lasers being so arranged that the emitted beams are almost parallel to one another in a slow-axis direction and the incidence angles of the emitted beams to the optical fiber differ from one another in a fast-axis direction.

Abstract: An up-conversion laser unit in which a semiconductor laser of high output power can be used as a pump light source and the wavelength of up-converted laser light is suitable for display. The light of infrared wavelength is generated by the pump light source, the generated light being inputted into a Pr3+ up-conversion laser to up-convert there into red light by Pr3+ ion. The up-converted red light is inputted into, as a pump light source, a Tm3+ up-conversion laser, there being up-converted into blue light by the Tm3+ ion. Thereby, efficient up-conversion into blue light is made possible.

Abstract: Light from a first excitation light source is incident on one facet of a first optical fiber. A core is doped with a first rare earth substance. A resonant section induces light resonance in the core to generate resonant light, thereby providing selected light at the other facet of the first optical fiber. An optical multi/demultiplexer reflects the light of the selected wavelength in a direction different from that of the first optical fiber. A second excitation light source supplies light to the resonant section of the first optical fiber via the optical multi/demultiplexer and the other facet of the first optical fiber. A second optical fiber guides the light of the selected wavelength from the optical multi/demultiplexer to an exterior.

Abstract: An induction charge mirror is provided which makes a rotation mirror which is operated under an electrostatic force hinge-free and achieves a greater aperture rate in a simpler structure and the easiness with which it is manufactured. To this end, a space is provided in an upper surface portion of the insulating substrate and surrounded at least its surface portion surrounded with an insulating material. A flat mirror conductor is tiltably set within the space. A transparent electrode and first and second fixed electrodes are provided. A means is provided for normally applying a first potential to the transparent electrode and, in order to switch the tilting angle of the mirror conductor, means are provided for alternately applying a second potential and third potential to the first and second fixed electrodes.

Abstract: Even if there is a temperature variation, a positional discrepancy at a colliding surface of an active surface of a semiconductor laser and an optical waveguide is suppressed, resulting in realization of a semiconductor light emitting element coupled with optical fiber of stable operation. In order to realize the above object, a semiconductor light emitting element coupled with optical fiber comprises a substrate, an optical waveguide disposed on the substrate and including a core and a cladding layer covering the core, a semiconductor light emitting element disposed on the substrate and comprising an output end-surface facing one end of the core of the optical waveguide, and an optical fiber comprising a core an end of which faces the other end of the core of the optical waveguide, wherein the cladding layer sandwiches both surfaces of the semiconductor light emitting element.