Abstract: A light diffuser containing light diffusing elements is arranged in the most appropriate position between a spatial light modulator and an illumination optical system. Thereby, particles as light diffusing elements diffuse rays of light emitted from a laser light source. Accordingly, indefinite numbers of speckle pattern are formed so that, for example, a speckle noise which occurs on an image projected to a screen is reduced. As a result, loss of light amount after light diffusion is suppressed to small amount, and thereby a laser image display apparatus capable of displaying a bright and high-quality image having no luminosity irregularity is provided.

Abstract: A wavelength conversion optical device is provided with a fundamental wave light source (301) which outputs a fundamental wave (L11) including a P polarized light and an S polarized light that are perpendicular to each other, and two wavelength conversion mechanisms (303a,303b) each having a polarization inversion formation part which wavelength-converts the fundamental wave (L11) to generate harmonic waves, and the first-stage wavelength conversion mechanism (303a) performs wavelength conversion of the P polarized light of the fundamental wave (L11) while the second-stage wavelength conversion mechanism (303b) performs wavelength conversion of the S polarized light of the fundamental wave (L11), whereby absorption of a second harmonic wave (green light) due to a third harmonic wave (ultraviolet light) is reduced, and stability and reliability of the wavelength-converted light output are enhanced, thereby providing a wavelength conversion optical device which can output a wavelength-converted light capable of

Abstract: In a two-dimensional image display device, speckle noise is reduced by a simple construction. A two-dimensional image display device for displaying an image by projecting coherent light onto a projection plane is provided with at least one coherent light source (1a), (1b), (1c) for outputting coherent light, a polarization state modulator 6 for modulating at least one of a polarization state and a phase of the coherent light emitted from the coherent light source, and a birefringent diffusion plate (7) for spatially varying the phase of the coherent light emitted from the polarization state modulator. The polarization states of light spots in the respective pixels of the image displayed on the projection plane are spatially and temporally varied, thereby forming various speckle patterns.

Abstract: An electric switch includes a ferroelectric substrate to which metal is added, a pair of electrodes provided on the ferroelectric substrate, and an electric field applying portion for changing the direction of polarization in part of the ferroelectric substrate.

Abstract: There is provided a stable optical element having a fine, uniform, and wide-ranging domain inversion structure in a ferroelectric crystal. This includes a plurality of domain inversions (101) formed on an MgO:LiNbO3 substrate (100), and a groove (102) formed on the substrate surface between the domain inversions (101). The depth T? of substantially all of the domain inversions (101) satisfies the relation T?<T with respect to the substrate thickness T.

Abstract: In a two-dimensional image display device, speckle noise is reduced by a simple construction. A two-dimensional image display device for displaying an image by projecting coherent light onto a projection plane is provided with at least one coherent light source (1a), (1b), (1c) for outputting coherent light, a polarization state modulator 6 for modulating at least one of a polarization state and a phase of the coherent light emitted from the coherent light source, and a birefringent diffusion plate 7 for spatially varying the phase of the coherent light emitted from the polarization state modulator, wherein the polarization states of light spots in the respective pixels of the image displayed on the projection plane are spatially and temporally varied, thereby forming various speckle patterns.

Abstract: A laser light source (10) of the present invention is provided with plural semiconductor lasers (1), and a waveguide (3) in which light beams emitted from the respective semiconductor lasers (1) propagate, and the plural semiconductor lasers are disposed at an upper end of an incident end face (31) of the waveguide so that the light beams (4) emitted from the respective semiconductor lasers enter the waveguide from the end face (31) of the waveguide and are emitted from another end face (32) of the waveguide. Thereby, it is possible to realize a high-power and compact laser light source which is able to output a light beam having a uniform light intensity distribution.

Abstract: An optical element (10) according to the present invention is provided with a plurality of waveguides (11)˜(13) and a plurality of light path coupling parts (21), (22) coupling adjacent waveguides so as to optically couple said plural waveguides serially, wherein the paths for transmitting lights through the plural waveguides are curved at the optical path coupling parts, thereby the optical elements which is converted the incident laser light into the emitted light having uniform cross-sectional light intensity distribution can give a compact structure, further a laser light source that employs the optical element, and a two-dimensional image forming apparatus that employs the laser light source can also give a compact structure.

Abstract: A method for forming a domain-inverted structure includes the following: using a ferroelectric substrate (1) having a principal surface substantially perpendicular to the Z axis of crystals; providing a first electrode (3) on the principal surface of the ferroelectric substrate, the first electrode having a pattern of a plurality of electrode fingers (5) that are arranged periodically; providing a counter electrode (6) on the other side of the ferroelectric substrate so as to be opposite from the first electrode; and applying an electric field to the ferroelectric substrate with the first electrode and the counter electrode, thereby forming domain-inverted regions corresponding to the pattern of the first electrode in the ferroelectric substrate. Each of the electrode fingers of the first electrode is located so that a direction from a base to a tip (5a) of the electrode finger is aligned with the Y-axis direction of the crystals of the ferroelectric substrate.

Abstract: In a display unit which makes coherent light perform scanning on a screen to display an image, it is necessary to rotate a polygon mirror at ultrahigh speed for display of a high resolution image such as HDTV, and therefore, a high-performance polygon mirror must be employed, and further, noise and power consumption during rotation of the polygon mirror cause problems. Mirrors for multiple reflection (6a) and (6b) are inserted in a coherent light scanning optical system, whereby plural scanning lines can be obtained while one plane of the polygon mirror (5) scans one line of coherent light, leading to reduction in the rpm of the polygon mirror.

Abstract: An electric switch includes a ferroelectric substrate to which metal is added, a pair of electrodes provided on the ferroelectric substrate, and an electric field applying portion for changing the direction of polarization in part of the ferroelectric substrate.

Abstract: A light diffuser containing light diffusing elements is arranged in the most appropriate position between a spatial light modulator and an illumination optical system. Thereby, particles as light diffusing elements diffuse rays of light emitted from a laser light source. Accordingly, indefinite numbers of speckle pattern are formed so that, for example, a speckle noise which occurs on an image projected to a screen is reduced. As a result, loss of light amount after light diffusion is suppressed to small amount, and thereby a laser image display apparatus capable of displaying a bright and high-quality image having no luminosity irregularity is provided.

Abstract: A method for forming a domain-inverted structure includes the following: using a ferroelectric substrate (1) having a principal surface substantially perpendicular to the Z axis of crystals; providing a first electrode (3) on the principal surface of the ferroelectric substrate, the first electrode having a pattern of a plurality of electrode fingers (5) that are arranged periodically; providing a counter electrode (6) on the other side of the ferroelectric substrate so as to be opposite from the first electrode; and applying an electric field to the ferroelectric substrate with the first electrode and the counter electrode, thereby forming domain-inverted regions corresponding to the pattern of the first electrode in the ferroelectric substrate. Each of the electrode fingers of the first electrode is located so that a direction from a base to a tip (5a) of the electrode finger is aligned with the Y-axis direction of the crystals of the ferroelectric substrate.

Abstract: A laser module includes: a sub-mount; a semiconductor laser secured to a surface of the sub-mount; and an optical waveguide device joined to the surface of the sub-mount by an adhesive layer so that the optical waveguide device is coupled optically with the semiconductor laser. A first groove is formed at the surface of the sub-mount at a region corresponding to an incident end side of the optical waveguide device, the first groove being formed parallel to an outgoing end face of the semiconductor laser with a predetermined space therefrom. The adhesive layer is formed so that an end of the adhesive layer on the incident end side of the optical waveguide device is positioned within a range from a position abutting with a distal edge of the first groove distant from the semiconductor laser to an inside of the first groove and does not contact with the outgoing end face of the semiconductor laser.

Abstract: In a short-wavelength laser module, long-term reliability is lost because of unnecessary gas deposited on the end face of its optical waveguide. A short-wavelength laser module has a package structure wherein a package lid used when the short-wavelength laser module is hermetically sealed does not make contact with internal gas, and a process of accelerating the polymerization of a securing agent used inside the package is incorporated, whereby unnecessary gas from the securing agent is eliminated and the long-term reliability of the output is attained.

Abstract: In a short-wavelength laser module, long-term reliability is lost because of unnecessary gas deposited on the end face of its optical waveguide. A short-wavelength laser module has a package structure wherein a package lid used when the short-wavelength laser module is hermetically sealed does not make contact with internal gas, and a process of accelerating the polymerization of a securing agent used inside the package is incorporated, whereby unnecessary gas from the securing agent is eliminated and the long-term reliability of the output is attained.

Abstract: 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.

Abstract: In a short-wavelength laser module, long-term reliability is lost because of unnecessary gas deposited on the end face of its optical waveguide.

Abstract: 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.