Abstract: A wavelength converter that is used in an optical communication system utilizing wavelength multiplexing. The wavelength converter has a quasi-phase matched quartz crystal that has a second-order nonlinear effect, and a light coupling device that mixes the signal light and control light and inputs this mixed light into the quasi-phase matched quartz crystal. The wavelength converter also has quartz type optical fibers between the light coupling device and the quasi-phase matched quartz crystal. The mode diameter of the quartz type optical fibers is substantially the same as the mode diameter of the optical waveguide.

Abstract: In an exhaust gas heat exchanger for a system where a compressing means is located upstream of an internal combustion engine, and a part of exhaust gas from the internal combustion engine flows into the intake gas at a merge part located upstream of the compressing means, the exhaust gas heat exchanger includes a heat exchanging member. The heat exchanging member is provided adjacently to the merge part, and exchanges heat between the intake gas and the part of the exhaust gas such that the part of the exhaust gas is cooled by the intake gas.

Abstract: Two grooves 10 are diced in parallel along the light passage direction in a quartz quasi-phase matching element 1. Consequently, as is shown in (b) and (c), a protruding part 11 which is positioned between the two grooves 10 is formed on the upper surface side (in the figures), and a ridge type waveguide 9 is formed inside this protruding part. Accordingly, if light is caused to pass through this ridge type waveguide 9, the light can be caused to pass through the portions with inverted crystal axes (polarization inversion regions) 4, and can be subjected to a wavelength conversion, in a state in which the light is confined into the ridge type wavelength guide 9. As a result, a state can be produced in which the energy of the light is high inside the wavelength conversion region, so that a high wavelength conversion efficiency can be obtained.

Abstract: The invention provides an incubator 1 wherein stackers 3 having a plurality of microplate accommodating portions are arranged in a chamber 11, and a microplate transport device 5 is arranged for transporting a microplate 31 within the chamber 11 and moving the microplate 31 into or out of a desired microplate accommodating portion. A camera 7 is provided on a position opposed to a microplate accommodating portion of an uppermost stage in the stacker 3. The camera 7 faces said microplate accommodating portion, whereby a sample on the microplate 31 can be photographed.

Abstract: In a brazed structure, a first member has a first portion defined by one of a recessed portion and a hole, and a second member has a second portion brazed to the first portion with a copper brazing material. The first member has a coefficient of thermal expansion that is smaller than that of the second member.

Abstract: A heat exchanger is disclosed. Side plates (4) each include a base portion (41), in contact with fins (11), and side wall portions (42) extending from the base portion (41) in the direction Y in which tubes (10) are stacked. The side wall portions (42) are formed with a bent deforming portion (421) to facilitate extension/shrinkage, of the side wall portions (42), in the longitudinal direction (X) of the tubes (10). The base portion (41) is formed with a pair of hooks (411) extending toward the surface of the bent deforming portion (421) in opposed relation to the base portion (41). In the case where the base portion (41) tends to be displaced, the hooks (411) come into contact with the bent deforming portion (421) to thereby suppress or prevent the displacement of the base portion (41).

Abstract: The invention provides an incubator 1 wherein stackers 3 having a plurality of microplate accommodating portions are arranged in a chamber 11, and a microplate transport device 5 is arranged for transporting a microplate 31 within the chamber 11 and moving the microplate 31 into or out of a desired microplate accommodating portion. A camera 7 is provided on a position opposed to a microplate accommodating portion of an uppermost stage in the stacker 3. The camera 7 faces said microplate accommodating portion, whereby a sample on the microplate 31 can be photographed.

Abstract: The upper block 12 contacts the bearing block 20, and the bearing block 20 is coupled to the upper plate 21. The upper block 12 has a protruding part 22 on the upper surface that is worked into a convex surface with a radius of R1, and the bearing block 20 has a recessed part 23 in the undersurface that is worked into a concave surface with a radius of R2 (R2>R1). As a result of such a construction being used, the pressing surface of the upper pressing plate 15 always conforms to the surface of the quartz crystal substrate 11 during pressing, so that a uniform load is applied to the quartz crystal substrate 11. As a result, the surface of the quartz crystal can be uniformly pressed in the hot pressing method.

Abstract: The signal light is coupled with control light that is emitted from a laser diode 3 by a WDM coupling device 2. The optical fiber 4 on one end of the WDM coupling device is mode-matched with the optical waveguide of the quasi-phase matched quartz crystal 1 by a V groove 1a. The output light generated by the difference frequency generation of the signal light and control light is again guided to the optical fiber 5 from the quasi-phase matched quartz crystal 1 by the other V groove 1a. Then, this light is incident on the optical filter 7, so that the signal light and control light are cut. The optical fiber 9 is connected to a fiber amplifier 10. In cases where a quasi-phase matched quartz crystal is used as the wavelength conversion element, the wavelength conversion efficiency drops compared to lithium niobate as a result of the nonlinear constants being small. The fiber amplifier 10 is installed in order to compensate for this.

Abstract: Rectangular protruding parts 2 are formed on the surface of one side of a quartz crystal substrate 1; these protruding parts 2 are formed as aggregates of rectangular protruding parts 4 of an even finer pattern. Recessed parts 5 which are lower than the surfaces of the protruding parts 4 are formed between the protruding parts 4; however, the width of these recessed parts 5 is narrow, so that when the protruding parts 4 are viewed on the macroscopic scale, numerous protruding parts 4 are aggregated, and appear to form single protruding parts 2. Such a quartz crystal substrate 1 is clamped between heater blocks from above and below, and the temperature of the quartz crystal substrate is elevated. At the point in time at which this temperature reaches a desired temperature, the substrate 1 is pressed by means of a press. Consequently, stress acts only on the portions corresponding to the protruding parts 4, so that the crystal axis components are inverted only in these portions.

Abstract: Two grooves 10 are diced in parallel along the light passage direction in a quartz quasi-phase matching element 1. Consequently, as is shown in (b) and (c), a protruding part 11 which is positioned between the two grooves 10 is formed on the upper surface side (in the figures), and a ridge type waveguide 9 is formed inside this protruding part. Accordingly, if light is caused to pass through this ridge type waveguide 9, the light can be caused to pass through the portions with inverted crystal axes (polarization inversion regions) 4, and can be subjected to a wavelength conversion, in a state in which the light is confined into the ridge type wavelength guide 9. As a result, a state can be produced in which the energy of the light is high inside the wavelength conversion region, so that a high wavelength conversion efficiency can be obtained.

Abstract: The invention provides an incubator 1 wherein stackers 3 having a plurality of microplate accommodating portions are arranged in a chamber 11, and a microplate transport device 5 is arranged for transporting a microplate 31 within the chamber 11 and moving the microplate 31 into or out of a desired microplate accommodating portion. A camera 7 is provided on a position opposed to a microplate accommodating portion of an uppermost stage in the stacker 3. The camera 7 faces said microplate accommodating portion, whereby a sample on the microplate 31 can be photographed.

Abstract: Laser systems, and optical elements for laser systems, are disclosed for providing a pumped laser light with improved output efficiency while having simple construction and simple alignment adjustment. A pump light flux from a diode pumping laser irradiates and thus pumps a solid-state laser crystal. The irradiation by the pump light flux is coaxial with an output laser beam produced by the laser crystal. The pump light flux is conducted by an optical element, preferably frustoconical in shape with an entrance face larger than an exit face, that functions as a light funnel. The entrance face is disposed proximal to the pumping laser 11, and the exit face is disposed proximally to the laser crystal 14. A portion of the pump light flux entering the entrance face passes through the optical element without being reflected by a side surface of the optical element. The remaining pump light flux reflects at least once by the side surface during passage through the optical element.

Abstract: A lean burn engine adapted to establish a specified air-fuel ratio leaner by predetermined rate than a stoichiometric air-fuel ratio in a range of low engine speeds and low engine loads is provided with an air intake system of a low speed type which provides a high charging efficiency in a range of low engine speeds and an exhaust system capable of eliminating a nitrogen oxide emission in the exhaust even during lean burning.

Abstract: A component mounting apparatus having a suction nozzle movable with a component held attracted thereto to mount the component in a mounting position on a board comprises a CCD camera for taking images of the component and the mounting position obliquely from above when the suction nozzle has been brought to above the mounting position with the component held attracted thereto, an image processing circuit for calculating the deviation of the position of the component relative to the mounting position based on image signals from the camera, and a control circuit for correcting the position of the component by moving the suction nozzle in a horizontal plane in accordance with the calculated deviation.

Abstract: An intake system for a multiple-cylinder engine a plurality of primary discrete intake passages and a plurality of secondary discrete intake passages. Each pair of primary discrete intake passage and the secondary discrete intake passage communicate with one of the cylinders. Both the primary and secondary discrete intake passages are straight and the primary discrete intake passage is provided with a primary valve member which is provided with an opening and is selectively positioned in a closed position where the primary valve member limits the effective cross-sectional area of the primary discrete intake passage to the cross-sectional area of the opening and in an open position where the primary valve member wide opens the primary intake passage.

Abstract: A method of converting gradation of a digital image data so as to reduce the number of gradation, a circuit thereof, a print density controlling apparatus for a printer and a printer using the method, in which the number of gradation being converted into one gradation is set smaller for the portion of low gradation of the original data than for the portion of high gradation thereof, so that the gradation of the low-gradation portion is smoothly varied visually in the image after gradation conversion.

Abstract: A suction apparatus for an engine is provided with an intake path which has an opening portion at one end, and the other end of which is connected to an intake pulsation generation source. A resonator is connected to a downstream portion of said intake path through a connecting pipe, for eliminating a (0.5+n)th-order (where n is an integer equal to or larger than 0) resonant wave in the intake path which is induced by a compression wave generated from said intake pulsation generation source toward the upstream side.

Abstract: An electrodynamic loudspeaker which comprises a diaphragm which cooperates with a magnet system by means of a moving coil which is connected to said diaphragm and an optical measuring system which comprises two elements--a light source and a detector. At least one of said elements is connected to a central portion of the magnet system and the detector supplies a voltage which substantially corresponds to the displacement of the diaphragm. The other element is connected to the diaphragm and the magnet system is provided with a channel which is disposed in the direct path between the two elements.In order to linearize the luminous intensity characteristic, in accordance with a preferred embodiment, the channel is filled with an optical fibre material. Light weight LED's and phototransistors may be used as the optical elements.