Abstract: An optical disk head having a short wavelength light source has an aperture diaphragm placed in the course of its focusing optical system which can change its aperture diameter depending on the pit size on an optical disk in order to allow recording on and reproducing from not only a short wavelength optical disk, but also a long wavelength optical disk. The aperture diameter is made larger for the smaller pit size and vice versa, and the light source output is adjusted depending on the aperture diameter so that the light amount coming from the disk surface to a photodetector cannot be changed with the aperture diameter.

Abstract: There is disclosed a harmonic light source which comprises: a laser light source for radiating a pumping laser beam; a laser active medium for performing a laser oscillation by receiving the laser beam from said laser light source, a resonator being formed between a reflecting surface and said laser active medium; and a harmonic generating medium provided in said resonator for generating a harmonic, and which serves to modulate the harmonic by applying a supersonic wave to one of said laser active medium and said harmonic generating medium.

Abstract: A semiconductor laser device comprises a semiconductor laser which oscillates a fundamental wave, and a transparent waveguide which is installed substantially in parallel to a direction of a cavity of the semiconductor laser and integral with the semiconductor laser, where second harmonics of the fundamental wave travel through the transparent waveguide and are emitted therefrom. The semiconductor laser and the transparent waveguide have a refractive index in a prescribed range respectively, and an output of second harmonics being significantly high in comparison to the prior art can be obtained.

Abstract: A second harmonic generator of the present invention utilizes Cerenkov radiation as a useful coherent short-wavelength light source. The second harmonic generator includes an aberration correction means to collimate the second harmonic to form a parallel plane wave having a high flatness. The aberration correction means is provided on an exit end face of a nonlinear waveguide which generates the second harmonic, and a glued cone prism, a cone prism having a conic exit end face changed in accordance with birefringence of the nonlinear waveguide, or a diffraction grating is used as the aberration correction means.

Abstract: A system for increasing frequency of a laser beam utilizes focused Cherenkov radiation. The system utilizes reflective/refractive properties of contiguous optics to achieve increased frequency, which provides a mechanism for alloy for increased density in such applications as optical disk technology.

Abstract: An optical device includes a phase-locked diodelaser array (10), a collimator lens (17), and behind the collimator lens a prism system (30, 34) of at least one prism to broaden the far field radiation pattern in the lateral plane (XY) and a spatial filter (19) to select a favored mode. The laser radiation is concentrated into a single, round and diffraction limited spot (V).

Abstract: A polarization-rotator (22) and a polarization-sensitive beam combiner (30') are arranged in the radiation path between a phase-locked diode laser array (10) radiating in a stable supermode and a collimator lens (46). The two radiation lobes (11, 12) are superposed so that a single radiation spot (S) can be obtained. The quality of the spot can be improved by an arrangement of a prism system (40) and a spatial filter (45) in the lateral far field.

Abstract: A phased-array semiconductor laser having a plurality of light emitting regions aligned in a line and providing correlation of the oscillation phases between adjacent light emitting regions, and including a beam controlling system for providing the phased-array semiconductor laser having a far-field pattern of a single-lobe.

Abstract: An optical system and a optical information processing equipment utilizing the same are disclosed. The optical system comprises a laser diode and a hologram lens has an interference fringe prepared by the interference of a beam having substantially the same intensity distribution and/or phase characteristic as that of a laser beam emitted from the laser diode with a beam having a desired characteristic. The laser beam from the laser diode is irradiated on the hologram lens so that its characteristic is converted into the desired characteristic.

Abstract: In an interferometry wherein a light beam from a light source is divided in two, one of which is used as a reference beam and the other beam is used as an inspecting beam, and the two beams are projected again on an identical plane so as to form an interference pattern; a wavelength scanning type laser diode interferometry characterized in that a laser diode is employed as the light source, and that an injection current of the laser diode is modulated thereby to scan a wavelength of the laser diode and to change an intensity distribution of the interference pattern.

Abstract: This invention is characterized in that a modified polarization prism or a modified half prism is used therein. Since photodetectors serving at the same time for light signal detection, for automatic focussing and for tracking are disposed at opposite sides of the optical source of a semiconductor laser, a single axis optical system can be realized and it is possible to reduce the optical head in size.

Abstract: A hologram lens of the present invention has a spherical hologram surface, the center of said spherical surface being in agreement with a focal point of the lens, and the radius of said spherical surface being in agreement with a focal distance of the lens. Therefore, the hologram lens of the invention produces little aberration.

Abstract: Herein disclosed is a system using a plurality of laser beams, in which the positions of the respective laser beams are detected as the differences between the outputs of detectors of an optical detector arrangement and controlled by the difference signals so that they may be held mutually precisely. This system finds its suitable application to an optical disk recording system or a laser beam printer.

Abstract: An optical scanning system wherein a light beam from a laser source is reflected by a rotating polygonal mirror and focused by a scanning lens into a scanning beam spot on the drum surface. A cylindrical lens disposed between the scanning lens and the drum for correcting the unevenness of the scanning line pitch caused by the incline of the each facet of the polygonal mirror has a curvature in the scanning direction of the beam so that optimal focal points of the scanning beam spot align on a straight line.

Abstract: In a laser beam scanner apparatus for scanning the surface of a photosensitive drum or a document to be read by deflecting a laser beam emitted from a laser diode with a deflector, there is provided a drive current control circuit for controlling the magnitude of drive current of said laser diode on the basis of a beam deflection angle of said deflector.

Abstract: An optical system for focusing a light beam emitted from a semiconductor laser is disclosed which comprises a lens of a numerical aperture NA satisfying a relation ##EQU1## (where .lambda. and .DELTA.Z indicate a laser wavelength of and an astigmatic focal distance in the semiconductor laser, respectively) to make the wave front aberration of a light beam emerging from the lens smaller than or equal to .lambda./4, thereby correcting astigmatism in the semiconductor laser.

Abstract: An optical system provided with a single optical scanner for separating a plurality of laser beams from each other and for leading the separated laser beams to different recording materials to record information thereon is disclosed in which cylindrical lenses are provided in front of the recording materials in such a manner that a predetermined number of ones among the laser beams pass through the cylindrical lenses, respectively.

Abstract: A two-beam scanning optical system comprising two laser beams each having a polarization characteristic, a first polarization beam splitter for compounding the two laser beams into one laser beam, a rotary polygonal mirror for scanning the compounded laser beam, a second polarization beam splitter for separating the compounded laser beam into two laser beams, and a lens system for focusing the separated laser beams onto a surface of a sensitive drum of a laser printer and onto a surface of an original document to be read, respectively, so that said two separated laser beams scan the respective surfaces of the sensitive drum and the original document.

Abstract: An apparatus for driving a semiconductor laser for use in a laser-beam printer, in which a laser beam from the laser is deflected so as to scan a light-sensitive drum and a light-sensitive detector placed in the vicinity of one edge of the drum, comprises a first device for determining the operation level for the laser when it scans the drum to record information thereon, a second device for determining the operation level for the laser when it scans the detector to provide a scanning start pulse signal and a controller for controlling the first and second devices so that they are alternately enabled to determine the intensity of the laser beam depending upon whether the drum or the detector is scanned, whereby the intensity of the laser beam is allowed to be adjusted in accordance with the varying light-sensitivity of the drum without fluctuating the instant of generation of the scanning start pulse signal.

Abstract: An optical head comprising a lens disposed at a position for forming spot images of a semiconductor laser having a plurality of lasing points, in which beams from the semiconductor laser are focused on a disc on which predetermined information is recorded by light.