Abstract: A laser apparatus comprises a plurality of laser beam sources for radiating out a plurality of laser beams such that the laser beams may intersect one another on a predetermined virtual plane, through which the laser beams pass. A Fourier transform lens array optical system, which divides the laser beams having impinged upon the virtual plane into small regions and carries out Fourier transform of the small regions, is located in the vicinity of the virtual plane. A laser resonator mirror optical system is constituted of a first laser resonator mirror, which is located at a position that receives the laser beams having been radiated out of the Fourier transform lens array optical system, and a second laser resonator mirror, which is located at a position rearward from the laser beam sources. The laser apparatus coherently combines the later beams with one another without reducing the radiant energy combining efficiency and thereby radiates out a combined laser beam having a high output power.

Abstract: A polarized light coherent combining laser apparatus comprises a unit, which is constituted of a compensating phase difference plate, a polarized light separating element, and a phase difference plate. A phase difference and an angle of inclination of principal axes of the phase difference plate are set so as to satisfy specific conditions in accordance with the intensity ratio between two linearly polarized laser beams, which impinge upon the unit. The two linearly polarized laser beams, which have the directions of polarization orthogonal to each other and which impinge upon the unit, are combined with each other by the polarized light separating element. The combined laser beam is converted by the phase difference plate into a beam polarized linearly in a predetermined direction. The resulting beam passes through an analyzer, is reflected by a radiating mirror, and again impinges upon the unit.

Abstract: A laser beam source radiates out laser beams such that they may intersect one another with predetermined angular spectra on a predetermined virtual plane. A Fourier transform lens array optical system, which is located in the vicinity of the virtual plane, divides the laser beams having impinged upon the virtual plane into small regions and carries out Fourier transform of the small regions. Phase modulators modulate the phases of the laser beams divided into the small regions such that the wave fronts of the laser beams after being subjected to the Fourier transform may have the same phase with respect to a predetermined direction as a whole. A scanning drive device drives the phase modulators such that the directions of travel of the laser beams radiated out of the Fourier transform lens array optical system may be changed. A first resonator mirror is located at a position that receives the scanned laser beams. A second resonator mirror is located at a position rearward from the laser beam source.

Abstract: A polarized light coherent combining laser apparatus comprises a plurality of units, each of which is constituted of a polarizing element and a phase difference plate. A phase difference and an angle of inclination of principal axes of the phase difference plate of each unit is set so as to satisfy specific conditions in accordance with the intensity ratio between an S-polarized laser beam and a P-polarized laser beam, which impinge upon each unit. The P-and S-polarized laser beams impinging upon each unit are combined with each other by the polarizing element. The plane of polarization of the combined laser beam is rotated by the phase difference plate, and the resulting laser beam impinges upon the next unit. The laser beam having been radiated out of the last unit passes through an analyzer, is reflected by a reflecting surface of a radiating mirror, and again impinges upon each unit. The laser beams having again impinged upon the units are then reflected by mirror surfaces of amplifying media.

Abstract: A light amplifying device comprising an optical oscillator constituted by first and second reflective mirrors and a common reflective mirror disposed in an optically opposite relation to each other, a polarized beam splitter for making a laser beam incoming from the side of the common reflective mirror incident on the first or second reflective mirror, and for making laser beams incoming from the sides of the first and second reflective mirrors incident on the common mirror, first and second amplifying media disposed in optical paths of the respective laser beams for amplifying the laser beams, and an optical element for rotating the polarizing plane of the laser beam reflected by the common reflective mirror by a predetermined angle.

Abstract: An optical amplifier includes a plurality of amplifiers which are disposed between a first reflective mirror and a second reflective mirror of an optical resonator arranged with the first reflecting mirror and the second reflecting mirror in face-to-face relationship and are adapted to amplify light through induced emission; and a beam combining and separating device which is adapted to combine the light made incident thereupon from the plurality of amplifiers and cause the light to emerge therefrom in the direction of the second reflecting mirror and is also adapted to separate the light from incident thereupon after being reflected by the second reflecting mirror and cause the light to emerge therefrom in the respective directions of the amplifiers. As the combination and separation of the light are repeatedly effected, a beam of light having high energy amplified by the amplifiers is obtained.

Abstract: An optical system featuring a semiconductor laser for oscillating a beam which has, in a far field pattern, two lobes in the direction aligned with a pn junction interface of the semiconductor laser. The optical system is provided with a total reflection mirror for reflecting part of the beam in such a manner that one of the two lobes is separated as a result of the reflection of part of the beam from the other, and with a polarization beam splitter having a junction for synthesizing rays in such a manner that the lobes which have been separated by the total reflection mirror are superimposed. The apparatus is thus capable of forming a single beam spot at which the two lobes are superimposed.

Abstract: A laser optical system for obtaining a Gaussian distribution by correcting a phase laser beam oscillating in multi-transverse mode oscillated from a phase synchronous semiconductor laser or a broad contact semiconductor laser. The phase is corrected by multiple concavo-convexities of a phase correction plate arranged parallel to the direction of generating the transverse mode. The phase correction plate is positioned downstream from a collimator which turns the laser beam into parallel light, that is, the phase correction plate is disposed through the collimated beam, i.c., in an area where the beam is magnified and is of optically equal value regardless of position. Therefore, adjustment of the position of the phase correction plate is easy and formation of the concavo-convexity pattern of the phase correction plate is easy.

Abstract: A light beam scanner for scanning a light beam not by using an optical part such as a rotary polygon mirror or a galvanometer but by using a phase-conjugate element (or phase-conjugate mirror) having a non-linear light effect to establish a phase conjugate beam due to four-light wave mixing. The phase-conjugate element constitutes a resonator, when irradiated with and excited by a pumping light beam, together with a reflecting face existing in its vicinity so that laser oscillations are effected inbetween. Between the phase-conjugate element and the reflecting face, there are interposed a plurality of optical gates, some of which are opened to constitute a resonator and to generate the laser oscillations and a conjugate laser beam for recording. Thus, the scanning operation can be accomplished by controlling the optical gates to be opened or closed.

Abstract: A laser optical system is designated to obtain Gaussian beams by correcting phases of laser beams emitted from a laser which oscillates on transverse multimodes. A spectral element is adapted to separate spectroscopically the laser beams in each transverse multimode which are emitted from the laser in such a way that the respective transverse modes for each order appear as their corresponding luminescent points on each of the phase correcting elements. A correction is performed by the phase correcting plate so that the phase between each adjacent luminescent point becomes the same phase, whereby the laser beams are reflected to the spectral element. The laser beams thus phase-corrected are combined into one, thereby obtaining Gaussian beams.

Abstract: A recording apparatus for recording information with a light beam, having a beam deflector for deflecting the light beam in the direction of main scan by a sine wave oscillation. The deflection angle of the light beam from the beam deflector is amplified in the direction of the main scan by means of an afocal anamorphic optical system. This arrangement makes it possible to effect the main scan with the light beam which has been deflected by the light deflector while the angle of oscillation of the light deflector is within a smallest region.