Abstract: A laser apparatus for selectively supplying a plurality of laser beams of 30 nm or more in wavelength difference to a measuring apparatus includes optical fibers through which the laser beams pass, and a switching and coupling means connected to the optical fibers for selecting at least one laser beam from a plurality of laser beams. A laser-applied apparatus includes this laser apparatus, and a fluorescent microscope, a DNA sequencer, or an examination apparatus selected from a DNA chip examination apparatus, protein examination apparatus and a DNA probe array examination apparatus.

Abstract: A laser apparatus for selectively supplying a plurality of laser beams of 30 nm or more in wavelength difference to a measuring apparatus includes optical fibers through which the laser beams pass, and a switching and coupling means connected to the optical fibers for selecting at least one laser beam from a plurality of laser beams. A laser-applied apparatus includes this laser apparatus, and a fluorescent microscope, a DNA sequencer, or an examination apparatus selected from a DNA chip examination apparatus, protein examination apparatus and a DNA probe array examination apparatus.

Abstract: In order to eliminate noise of a solid state laser apparatus generating a blue light wave, the solid state laser apparatus comprises a solid state laser light source, an optical modulator having a light modulating function and outputting the modulated light therefrom as a desired light output, a photo-detector converting one part of output light from the solid state laser light source to an electrical signal, an electrical circuit detecting a noise component from the electrical signal and moving the phase of an electrical signal corresponding to the noise component, and a controller for applying the output signal of the electrical circuit to the optical modulator so as to substantially eliminate light of the blue light wave corresponding to the noise component so as to provide the desired light output from the optical modulator.

Abstract: A second harmonic generator comprising a semiconductor laser as an excitation light source and a resonator having a solid laser crystal excited by the excitation light source, a control element for controlling the wavelength of a first oscillation wave generated from the solid laser crystal and a nonlinear crystal for wavelength converting the first oscillation wave as a fundamental wave into a second harmonic wave as a second oscillation wave, wherein the components of the resonator are arranged in the order of a first laser mirror, solid laser crystal, wavelength control element, nonlinear crystal and second laser mirror from the input side of the excitation light.

Abstract: A laser having, a resonator structure including a wavelength variable laser crystal containing a fluoride and an optical part for controlling the wavelength of radiation from the laser crystal, a device to excite the laser crystal, a device for detect reflected light from the optical part as a sample beam, and a device to stabilize the output of a laser beam from the resonator structure based on the sample beam.

Abstract: A second harmonic generating apparatus including a semiconductor laser serving as a pumping source, a resonator structure for oscillating a first radiation wave generated by LiSAF (Cr:LiSrAlF.sub.6 : Lithium strontium aluminum fluoride with chromium added) crystal which is a solid-state laser crystal which is excited by the pumping source, a control element for controlling the wavelength of the first oscillation wave, and a nonlinear crystal for performing wavelength conversion into second harmonic which is a second oscillation wave, with the first oscillation wave serving as a fundamental wave, the nonlinear crystal being provided in the resonator. A higher efficiency and reliability of the second harmonic generating apparatus is achieved.

Abstract: A laser apparatus including a laser crystal composed of a fluoride which contains chromium (Cr), a resonator which includes the laser crystal, a means for exciting the laser crystal, a first laser beam produced from light which is emitted from the laser crystal and oscillated in the laser resonator, and at least one optical component which is inserted in said resonator; wherein an aperture in the resonator is substantially five or more times the diameter of the first laser beam. A small, low-power SHG laser light source is achieved.

Abstract: A short-wavelength laser having a stable output and an optical information processing system capable of high-density recording are disclosed. A solid-state laser is used as a light source, and a nonlinear optical crystal is arranged in a resonator in order to produce a short wavelength by means of a solid-state laser. The retardation of the nonlinear optical crystal is controlled by determining the length of the nonlinear optical crystal. A solid-state laser device having a stable output with the noise removed from a pumping power light source is also provided. Further, the solid-state laser device is used as a light source for the optical information processing system, and the light of irrelevant wavelengths contained in the light from the solid-state laser device are removed by a device having the ability to select wavelengths. Thus, not only a stable light source with a short wavelength but also an optical information processing system capable of high-density recording are realized.