Abstract: Provided are a high-energy and high-powered laser light source and a photoemission electron microscope using the laser light source. The laser light source 2 is intended for use in the photoemission electron microscope for emitting a quasi-continuous wave laser 7 and includes: a first laser light source 100 configured to emit a continuous wave coherent light 100a, an optical resonator 110 including an optical path in which the continuous wave coherent light 100a circulates and including a non-linear optical element 114 disposed on the optical path, and a quasi-continuous wave light source 120 configured to emit a quasi-continuous wave coherent light 120a having a wavelength shorter than that of the continuous wave coherent light 100a and having a near rectangular output waveform.

Abstract: Provided is a swept light source including one end surface coupled to a wavelength filter constituted of a diffraction grating and an end mirror via a light deflector and another end surface including a gain medium facing an output coupling mirror and which configures a laser cavity between the end mirror and the output coupling mirror, wherein a drive voltage having an AC voltage on which a DC bias voltage is superimposed is output from a control voltage source of the light deflector to an electrode pair of an electro-optic crystal, light is radiated from a light emitter to the electro-optic crystal, and incident light from the gain medium incident along an optical axis perpendicular to a direction of an electric field formed by the control voltage is deflected in a direction parallel to the electric field, so that wavelength sweeping is performed.

Abstract: Provided is a swept light source including one end surface coupled to a wavelength filter constituted of a diffraction grating and an end mirror via a light deflector and another end surface including a gain medium facing an output coupling mirror and which configures a laser cavity between the end mirror and the output coupling mirror, wherein a drive voltage having an AC voltage on which a DC bias voltage is superimposed is output from a control voltage source of the light deflector to an electrode pair of an electro-optic crystal, light is radiated from a light emitter to the electro-optic crystal, and incident light from the gain medium incident along an optical axis perpendicular to a direction of an electric field formed by the control voltage is deflected in a direction parallel to the electric field, so that wavelength sweeping is performed.

Abstract: Highly-qualified crystals are grown with good yield under an optimal temperature condition by controlling the axial temperature distribution in the vicinity of the seed crystal locally. In an apparatus for producing crystals to grow crystals wherein a seed crystal 14 is placed in a crucible 11 which is retained in a furnace, raw materials 12 filled in the crucible 11 are heated and liquefied, and a raw material 12 slowly cooled in the crucible 11 from below upward, the apparatus including a temperature controller for controlling temperature to cool or heat the vicinity of the seed crystal 14 locally. The temperature controller controls the temperature by a hollow constructed cap 17 mounted outside the portion of crucible 11 and regulates refrigerant flow running through the hollow portion.

Abstract: An electrooptic device having a simple structure that can efficiently increase deflection of a beam is provided. The device includes: an electrooptic crystal (11) having an electrooptic effect; an electrode pair of a positive electrode (12) and a negative electrode (13) for generating an electric field inside the electrooptic crystal; and a power source for applying a voltage between the electrode pair so as to generate a space charge inside the electrooptic crystal. With this arrangement, by using a simple structure, a change in a deflection angle is temporally rapid, and a large deflection angle that cannot be obtained by a conventional electrooptic crystal prism can be acquired at a low applied voltage.

Abstract: An electrooptic device having a simple structure that can efficiently increase deflection of a beam is provided. The device includes: an electrooptic crystal (11) having an electrooptic effect; an electrode pair of a positive electrode (12) and a negative electrode (13) for generating an electric field inside the electrooptic crystal; and a power source for applying a voltage between the electrode pair so as to generate a space charge inside the electrooptic crystal. With this arrangement, by using a simple structure, a change in a deflection angle is temporally rapid, and a large deflection angle that cannot be obtained by a conventional electrooptic crystal prism can be acquired at a low applied voltage.

Abstract: The present invention provides a small spectroscope that has a short response time. A spectroscope according to one embodiment of the present invention includes: a beam deflector that includes an electro-optic crystal, having an electro-optic effect, and paired electrodes used to apply an electric field inside the electro-optic crystal; spectroscopic means for dispersing light output by the beam deflector; and wavelength selection means for selecting light having an arbitrary wavelength from the light dispersed and output by the spectroscopic means.

Abstract: An electrooptic device having a simple structure that can efficiently increase deflection of a beam is provided. The device includes: an electrooptic crystal (11) having an electrooptic effect; an electrode pair of a positive electrode (12) and a negative electrode (13) for generating an electric field inside the electrooptic crystal; and a power source for applying a voltage between the electrode pair so as to generate a space charge inside the electrooptic crystal. With this arrangement, by using a simple structure, a change in a deflection angle is temporally rapid, and a large deflection angle that cannot be obtained by a conventional electrooptic crystal prism can be acquired at a low applied voltage.

Abstract: To provide a variable-focal length lens capable of altering its focal length at high speed. The variable-focal length lens has an electrooptic material and electrodes formed on an incident surface of light and on an exit surface of the light of the electrooptic material. An optical axis is set so that the light is inputted into a gap where the electrodes of the incident surface are not formed and is outputted from a gap where the electrodes of the exit surface are not formed. A focus of the light that is transmitted through the electrooptic material becomes variable by varying an applied voltage between the electrodes of the incident surface and the electrodes of the exit surface.

Abstract: An optical fiber, which has a zero-material dispersion wavelength equal to or greater than 2 ?m, and a high nonlinear susceptibility ?3 equal to or greater than 1×10?12 esu, and uses tellurite glass having sufficient thermal stability for processing into a low loss fiber, employs a PCF structure or HF structure having strong confinement into a core region. This enables light to propagate at a low loss. The size and geometry of air holes formed in the core region, and the spacing between adjacent air holes make it possible to control the zero dispersion wavelength within an optical telecommunication window (1.2-1.7 ?m), and to achieve large nonlinearity with a nonlinear coefficient ? equal to or greater than 500 W?1 km?1.

Abstract: The present invention provides a small spectroscope that has a short response time. A spectroscope according to one embodiment of the present invention includes: a beam deflector that includes an electro-optic crystal, having an electro-optic effect, and paired electrodes used to apply an electric field inside the electro-optic crystal; spectroscopic means for dispersing light output by the beam deflector; and wavelength selection means for selecting light having an arbitrary wavelength from the light dispersed and output by the spectroscopic means.

Abstract: The present invention relates to an electric field sensor including: a light source (1); an electro optic crystal (7) which is applied with an electric field based on a signal under test, in which a birefringent index changes according to the electric field, and which changes a polarization state of light incident from the light source according to the birefringent index and emits the light; and a detector (9, 17, 19, 21) that detects an electric signal according to the change of the polarization state of the light emitted from the electro optic crystal (7). Further, the electric field sensor includes: a signal electrode (11) for applying the electric field based on the signal under test to the electro optic crystal (7); a counter electrode (12) that forms a pair with the signal electrode (11); and an auxiliary electrode (61) that is electrically connected to the counter electrode (12), and that forms a capacitance with ground.

Abstract: To provide a variable-focal length lens capable of altering its focal length at high speed. The variable-focal length lens has an electrooptic material and electrodes formed on an incident surface of light and on an exit surface of the light of the electrooptic material. An optical axis is set so that the light is inputted into a gap where the electrodes of the incident surface are not formed and is outputted from a gap where the electrodes of the exit surface are not formed. A focus of the light that is transmitted through the electrooptic material becomes variable by varying an applied voltage between the electrodes of the incident surface and the electrodes of the exit surface.

Abstract: An electrooptic device having a simple structure that can efficiently increase deflection of a beam is provided. The device includes: an electrooptic crystal (11) having an electrooptic effect; an electrode pair of a positive electrode (12) and a negative electrode (13) for generating an electric field inside the electrooptic crystal; and a power source for applying a voltage between the electrode pair so as to generate a space charge inside the electrooptic crystal. With this arrangement, by using a simple structure, a change in a deflection angle is temporally rapid, and a large deflection angle that cannot be obtained by a conventional electrooptic crystal prism can be acquired at a low applied voltage.

Abstract: An electrooptic device having a simple structure that can efficiently increase deflection of a beam is provided. The device includes: an electrooptic crystal (11) having an electrooptic effect; an electrode pair of a positive electrode (12) and a negative electrode (13) for generating an electric field inside the electrooptic crystal; and a power source for applying a voltage between the electrode pair so as to generate a space charge inside the electrooptic crystal. With this arrangement, by using a simple structure, a change in a deflection angle is temporally rapid, and a large deflection angle that can not be obtained by a conventional electrooptic crystal prism can be acquired at a low applied voltage.

Abstract: A fabrication method of an optical fiber using as a core material tellurite glass. The method includes a first process of molding a tellurite glass melt into a mold, the mold having a plurality of convex portions defining an inner wall, which portions run parallel to each other in a longitudinal direction in order to make a polygon columnar glass preform, and a second process of inserting the glass preform into a cylindrical jacket tube made of tellurite glass and carrying out fiber-drawing under pressure so as to maintain or enlarge air holes which are gaps generated between the glass preform and the jacket tube.

Abstract: An optical medium having a high refractive index without anisotropy and a wide transmission wavelength is obtained. The cubic crystal material is ??O3, where ? is at least one of K, Ba, Sr, Ca, and ? is at least one of Ta, Ti. Optimally, the cubic crystal material is KTa1-xNbxO3, where composition x is 0?x?0.35. This composition enables to raise refractive index while its phase transition temperature is below a room temperature.

Abstract: A method and an apparatus for producing crystals wherein crystal quality can be kept and a crystal composition is uniformed from a growth early stage to a growth last stage are provided. In an apparatus for producing crystals wherein the crystals 13 are grown from a liquefying raw material 12 in a crucible retained in a furnace and slowly cooling the raw material 12 in the crucible 11 from below upward, the apparatus comprises a raw material supply apparatus 18 which supplies a resupply raw material, and a reflection plate 20 placed above the crucible 11, which liquefies the resupply raw material 19 supplied from the raw material supply apparatus 18 and drops it as a liquid into the crucible.

Abstract: An electrooptic device having a simple structure that can efficiently increase deflection of a beam is provided. The device includes: an electrooptic crystal (11) having an electrooptic effect; an electrode pair of a positive electrode (12) and a negative electrode (13) for generating an electric field inside the electrooptic crystal; and a power source for applying a voltage between the electrode pair so as to generate a space charge inside the electrooptic crystal. With this arrangement, by using a simple structure, a change in a deflection angle is temporally rapid, and a large deflection angle that can not be obtained by a conventional electrooptic crystal prism can be acquired at a low applied voltage.

Abstract: An optical fiber, which has a zero-material dispersion wavelength equal to or greater than 2 ?m, and a high nonlinear susceptibility ?3 equal to or greater than 1×10?12 esu, and uses tellurite glass having sufficient thermal stability for processing into a low loss fiber, employs a PCF structure or HF structure having strong confinement into a core region. This enables light to propagate at a low loss. The size and geometry of air holes formed in the core region, and the spacing between adjacent air holes make it possible to control the zero dispersion wavelength within an optical telecommunication window (1.2-1.7 ?m), and to achieve large nonlinearity with a nonlinear coefficient ? equal to or greater than 500 W?1 km?1.