摘要:
An optical pickup and an optical information recording/reproducing device are provided, each of which is capable of forming a super-resolution spot to conduct micro-mark recording, and does not undergo signal degradation due to an increased sidelobe in a reproducing operation. A variable phase filter having three regions to produce a phase difference in a radial direction is used, to provide a phase difference of π between the center region and the side regions in a recording operation, so that a super-resolution spot is formed on a recording layer of the optical disk. In a reproducing operation, a phase difference is nullified between the regions of the variable phase filter, so that a normal light spot at a diffraction limit having a smaller sidelobe is formed. The variable phase filter can be formed with a homogeneous-alignment liquid crystal element.
摘要:
An optical waveguide device is provided that can reduce external interference noise. The optical waveguide device includes a substrate, an optical waveguide formed on the substrate, a periodic polarization inversion region formed on the optical waveguide, and an optical thin film formed in a portion of the optical waveguide. The optical waveguide (refractive index: N2) and the optical thin film (refractive index: N1) differ in refractive index dispersion, and the magnitude relationship between the refractive indexes is reversed depending on wavelength. The relationship N1>N2 is established for light having a shorter wavelength, while the relationship N2>N1 is established for light having a longer wavelength.
摘要:
The present invention aims to simplify a mass production process of an optical waveguide device and to reduce cost as well as noise. The optical waveguide device includes an optical waveguide whose entrance end face and exit end face are substantially parallel to each other. A SHG device is mass-produced by optically polishing an optical material substrate with a large area and then cutting the substrate. This method can mass-produce the optical waveguide devices having a uniform device length. The angle between the exit end face of the optical waveguide and the direction of an optical axis of the optical waveguide at the exit end face is not 90°, thereby reducing return light from the exit end face.
摘要:
An object of the present invention is to provide a coherent light source with limitations on the wavelength of emitted light being relaxed. The coherent light source of the present invention is a coherent light source for simultaneously emitting a first light (3) and a second light (4) having a wavelength shorter than that of the first light (3), including: a light source main body emitting at least the first light (3); a mirror (5) which transmits or reflects the first light (3); and a functional film (6) provided on at least a part of the mirror (5). The functional film (6) has a photocatalytic effect to be induced by the second light (4).
摘要:
A light source device can attain a stable output of a harmonic even when there occurs a change in the ambient temperature or fluctuation in the output power. The light source device is provided with a semiconductor laser source (4), an optical waveguide-type QPM-SHG device (5) for generating a second harmonic from light emitted from the semiconductor laser source (4), a wavelength control means (7) for controlling a wavelength of light emitted from the semiconductor laser source (4), a means for slightly fluctuating wavelength (8) for changing a wavelength of light emitted from the semiconductor laser source (4) and a means for detecting a change in output light power of the optical waveguide-type QPM-SHG device (5) that occurs when a wavelength of light emitted from the semiconductor laser source (4) is changed. In this case, a wavelength of light emitted from the semiconductor laser source (4) is controlled to an optimum wavelength of the optical waveguide-type QPM-SHG device (5) based on a change in output light power of the optical waveguide-type QPM-SHG device (5) that occurs when a wavelength of light emitted from the semiconductor laser source (4) is changed.
摘要:
An optical waveguide device includes a dielectric substrate; and an optical waveguide formed in the dielectric substrate, the optical waveguide having a longitudinal axis and an outgoing surface disposed at an angle other than a right angle relative to a plane perpendicular to the longitudinal axis.
摘要:
In a coherent light source in which limitations on the wavelength of emitted light are relaxed, a coherent light source for simultaneously emitting a first light (3) and a second light (4) having a wavelength shorter than that of the first light (3), includes: a light source main body emitting at least the first light (3); a mirror (5) which transmits or reflects the first light (3); and a functional film (6) provided on at least a part of the mirror (5). The functional film (6) has a photocatalytic effect to be induced by the second light (4).
摘要:
A reflection-type laser projector (100) projects modulated laser beams outputted from a laser projection unit (40), on a screen, wherein a reflector (112) as a constituent of the screen (110) has reflection characteristics of reflecting, among the incident light, only laser beams of three colors of red, blue, and green, which are projected from the laser projection unit (40) and light in the neighboring wavelength band, and transmitting light in other wavelength bands, thereby preventing pictures on the screen (110) from becoming hard to be seen due to effects of indoor illumination or light from outdoors.
摘要:
The present invention provides a reflection-type laser projector (100) which projects modulated laser beams outputted from a laser projection unit (40), on a screen, wherein a reflector (112) as a constituent of the screen (110) has reflection characteristics of reflecting, among the incident light, only laser beams of three colors of red, blue, and green, which are projected from the laser projection unit (40) and light in the neighboring wavelength band, and transmitting light in other wavelength band, thereby preventing pictures on the screen (110) from becoming hard to be seen due to effects of indoor illumination or light from outdoors.
摘要:
An optical waveguide device includes a dielectric substrate; and an optical waveguide formed in the dielectric substrate, the optical waveguide having a longitudinal axis and an outgoing surface disposed at an angle other than a right angle relative to a plane perpendicular to the longitudinal axis.