Abstract: A lighting apparatus includes a laser lighting module, an LED lighting module, and a sensor module. The laser lighting module includes a base part, a laser diode mounted on a substrate fixed on the base part, a ceramic phosphor upon which a blue laser light from the laser diode is incident, and a lens for adjusting luminous intensity distribution of light emitted from the ceramic phosphor, and is mounted on a module mount part of a mount body part. The LED lighting module and the sensor module are also mounted on other module mount parts of the mount body part, respectively. Thus, by mounting various combinations of the laser lighting modules and the LED lighting modules on the mount body part provided with a plurality of module mount parts, it is possible to manufacture lighting apparatuses for various uses at low cost.

Abstract: A laser lighting module includes a base part, a laser diode which is a blue laser device, a substrate with which the laser diode is in contact, a ceramic phosphor which reflects light entering from the laser diode to thereby change a direction of the light and is excited by the light to generate yellow fluorescence, and a lens for adjusting luminous intensity distribution of light emitted from the ceramic phosphor. The substrate is formed of a material which is thin and has excellent thermal conductivity, and is in surface contact with the laser diode and the base part. In the laser lighting module, since the substrate serves as a device heat radiator, it is possible to easily remove the heat generated by the laser diode.

Abstract: A process is disclosed for continuously producing a single crystal by drawing downwardly a melt of a single crystal raw material, wherein a single crystal body grown from the melt is continuously pulled downwardly, and a plurality of single crystal products are continuously formed by intermittently cutting the single crystal body being downwardly moved.

Abstract: A process is disclosed for continuously producing a single crystal by drawing downwardly a melt of a single crystal raw material, wherein a single crystal body grown from the melt is continuously pulled downwardly, and a plurality of single crystal products are continuously formed by intermittently cutting the single crystal body being downwardly moved.

Abstract: A process is disclosed for continuously producing a single crystal by drawing downwardly a melt of a single crystal raw material, wherein a single crystal body grown from the melt is continuously pulled downwardly, and a plurality of single crystal products are continuously formed by intermittently cutting the single crystal body being downwardly moved.

Abstract: A wavelength conversion device exhibiting an excellent wavelength conversion efficiency is provided by forming it in such a manner that an LiTaO.sub.3 substrate is subjected to a proton exchange treatment to form a proton-exchange layer before the proton-exchange layer is subjected to heat treatment to form a domain-inverted structure. Heat treatment is performed at a high temperature rising speed to prevent the thermal diffusion of the proton-exchange layer so that the expansion of the domain-inverted structure to be formed in the proton-exchange layer is restrained. As a result, a higher harmonic wave wavelength conversion device can be provided.

Abstract: A frequency doubler of the invention employs a nonlinear optical effect of stabilizing the harmonic output from the frequency doubler. The frequency doubler has an LiNbO.sub.3 substrate, domain inverted regions and a waveguide, which are formed on the substrate, and a thin-film heater formed on the waveguide by depositing Ni-Cr. The temperature of the frequency doubler is controlled by applying a current to the thin-film heater so as to heat the frequency doubler. Even if the wavelength of a semiconductor laser is changed due to change in the environmental temperature, the frequency doubler can stably be operated by changing the temperature of the frequency doubler.

Abstract: A wavelength conversion device exhibiting an excellent wavelength conversion efficiency is provided by forming it in such a manner that an LiTaO.sub.3 substrate is subjected to a proton exchange treatment to form a proton-exchange layer before the proton-exchange layer is subjected to heat treatment to form a domain-inverted structure. Heat treatment is performed at a high temperature rising speed to prevent the thermal diffusion of the proton-exchange layer so that the expansion of the domain-inverted structure to be formed in the proton-exchange layer is restrained. As a result, a higher harmonic wave wavelength conversion device can be provided.

Abstract: A method to fabricate nonlinear optical frequency doubler devices comprised of a process to form periodic tantalum masks on a LiNb.sub.x Ta.sub.1-x O.sub.3 (wherein 0.ltoreq.x.ltoreq.1) crystal substrate, a process to form periodic proton exchanged regions by applying a phosphoric acid treatment, and a process to form an optical waveguide on the surface of said crystal.According to this fabrication method of the present invention, deeper domain-inverted regions can be formed on said crystal surface, and by this, a fundamental wave can be transformed into a harmonic wave at a high efficiency.

Abstract: A tapered light wave guide reduced in propagation loss, improved in coupling efficiency and free from the problem of optical damage. An input section, a widthwise tapered coupling section having a depth d2, and a wave guide having a depth d1 are formed on an LiNbO.sub.3 substrate. A depthwise tapered section in which the depth is changed from d2 to d1 is provided to connect the widthwise tapered coupling section having constant depth d2 and the wave guide, whereby a reduction in light propagation efficiency due to optical damage is prevented.

Abstract: When fabricating an optical wavelength by proton exchange method on a substrate of LiNb.sub.x Ta.sub.1-x O.sub.3 (0.ltoreq.x.ltoreq.1), by using Ta.sub.2 O.sub.5 as the protective mask, the edge of the mask becomes smooth and diffusion of impurity from the protective mask into the substrate does not occur during heat treatment, and the propagation loss may be notably reduced. As a result, the efficiency of the frequency doubler may be enhanced.

Abstract: A visible laser source comprises a sub mount. A semiconductor laser located on the sub mount has an active layer formed at a surface of the semiconductor laser. The active-layer formed surface of the semiconductor laser opposes the sub mount. An optical nonlinear device located on the sub mount has a waveguide formed at a surface of the optical nonlinear device. The waveguide formed surface of the optical nonlinear device opposes the sub mount. The semiconductor laser and the waveguide are directly coupled to each other for direct application of a fundamental wave from the semiconductor laser to the optical nonlinear device.

Abstract: An optical harmonic generating device having a proton-exchanged optical waveguide possessing an upward convex shape and a structure capable of propagating in a single mode, an input part for receiving an optical wave having a fundamental frequency and an output part for outputting a harmonic wave, disposed on a substrate of LiNb.sub.x Ta.sub.1-x O.sub.3 (O.ltoreq.x.ltoreq.1). The device is an optical harmonic wave generating device with excellent confinement of light, optimum structure and high efficiency.

Abstract: In an optical fiber type temperature detector using temperature change of refraction index in birefringent crystal, by using LiTaO.sub.3 or Sr.sub.x Ba.sub.l-x Nb.sub.2 O.sub.6 single crystal (0.5<x<1.0) as material (13) for sensor and quartz as material for setting temperature range, a high sensitive and highly stable temperature detector using light emitting diode as light source is realized. Furthermore, as configuration of sensor part, miniaturization and light weight is devised by disposing rutile (11) or calcite between optical fibers (8, 9) and rod lens (12) to make polarization separation.

Abstract: A fiber optic magnetic field sensor employing Faraday effect. The sensor has two pieces of birefringent substance interposed between the ends of optical fibers and a rod lens for effecting polarization separation. In addition, the sensor employs a reflex optical system in which light reciprocates through a Faraday material. Thereby, a magnetic field sensor has been realized which is more compact and lightweight and lower in cost as well as more accurate.