Abstract: The present invention is intended to provide a compact and simple optical semiconductor device that reduces crosstalk (leakage current) between light receiving elements. According to the present invention, since a back surface electrode is a mirror-like thin film, crosstalk to an adjacent light receiving element can be suppressed, thereby reducing a detection error of a light intensity. By disposing a patterned back surface electrode or by disposing an ohmic electrode at the bottom of an insulating film over the whole back surface, contact resistance on the back surface can be reduced. By using the optical semiconductor elements with a two-dimensional arrangement and by using a mirror-like thin film as the back surface electrode, crosstalk can be reduced. By accommodating the optical semiconductor elements in the housing in a highly hermetic condition, the optical semiconductor elements can be protected from an external environment.

Abstract: An intake silencer of a gas turbine capable of efficient noise reduction in which a high frequency sound-absorbing splitter group composed of a plurality of sound-absorbing splitters capable of reducing highfrequency component noise and a middle/low sound-absorbing splitter group composed of a plurality of sound-absorbing splitters capable of reducing middle/low frequency component noise are disposed separately in a gas flow direction. High frequency component noise is reduced by the high frequency sound-absorbing splitter group, and middle/low frequency component noise is reduced by the middle/low sound-absorbing splitter group.

Abstract: An optical module has a structure for reducing the stress applied to a package. The optical module is structured so that an end face of a waveguide (37) of a planar lightwave circuit (30) is joined to a plurality of packages (40) storing therein optical elements so that the waveguide is optically coupled to the optical elements. The optical module includes a housing (3) storing therein a planar lightwave circuit and a plurality of packages in which an upper face of a protrusion (270) formed in the bottom section is fixed to the planar lightwave circuit (30). Each of the plurality of packages (40) is electrically connected to an electric part (22) provided in the housing (3) via flexible printed circuits (271a, 271b).

Abstract: An optical modulator having a high stability is provided. In the optical modulator according to the present invention, a phase modulation by an electro-optic effect is made on an optical substrate of an electro-optic material while the setting of an operating point by a thermal-optic effect is made on a planar lightwave circuit (PLC) substrate of quartz, silicon, or the like. Such configuration can suppress the influence of thermal drift or the like because no heat is applied directly to the optical substrate of the electro-optic material. In addition, breakage and warpage of the substrate due to heat are also mitigated. Further, quartz used for the PLC has a low thermal conductivity, approximately one-fifth of that of the LN substrate (approximately 1 W/(m·K)), and therefore, a desired phase difference can be maintained with a low power consumption, and thus, the operating point becomes stabilized.

Abstract: In an optical component configured to fix to a mount an optical device chip in which a plurality of waveguide type optical devices having different thermal expansion coefficients are butt-jointed, deterioration in reliability due to thermal stress is suppressed. The optical component (300) comprises an optical device chip (310) including an LN waveguide (311), a first PLC waveguide (312) connected to an end of the LN waveguide (311), a second PLC waveguide (313) connected to the other end of the LN waveguide (311), and a fiber alignment member (314) connected to the first PLC waveguide (312), a mount (320) on which the optical device chip (310) is mounted, and optical fibers (330) aligned to the fiber alignment member (314).

Abstract: In an optical component, a part of a waveguide type optical device is fixed to a convex portion of a mount. The optical component includes an optical support base, a pressure member and a pressure support base. The optical device support base is interposed between the mount and the presser member enough to be slidable in a direction parallel to surfaces of the mount and the presser member.

Abstract: Disclosed is an optical modulator which substantially lowers loss and has little attenuation in the intensity of an optical signal after modulation. The optical modulator includes a 1×2 RZ pulse carver wherein optical phase shifters used for modulation are arranged along two arm waveguides held between a 1×2 coupler and a 2×2 coupler, two interferometric modulators connected respectively to two output ports of the 2×2 coupler, and a 2×1 coupler for combining the outputs of the interferometric modulators.

Abstract: The present invention is intended to provide a compact and simple optical semiconductor device that reduces crosstalk (leakage current) between light receiving elements. According to the present invention, since a back surface electrode is a mirror-like thin film, crosstalk to an adjacent light receiving element can be suppressed, thereby reducing a detection error of a light intensity. By disposing a patterned back surface electrode or by disposing an ohmic electrode at the bottom of an insulating film over the whole back surface, contact resistance on the back surface can be reduced. By using the optical semiconductor elements with a two-dimensional arrangement and by using a mirror-like thin film as the back surface electrode, crosstalk can be reduced. By accommodating the optical semiconductor elements in the housing in a highly hermetic condition, the optical semiconductor elements can be protected from an external environment.

Abstract: In a nest MZI modulator in which each arm includes a child MZI, the power consumption is reduced. The hybrid integrated-type nest MZI modulator of the embodiment 1a is configured so that, instead of placing a relative phase adjusting section in a parent MZI, a bias electrode Bias 90° in which an electric field is applied in the same direction to the polarization direction in both of the upper and lower arms is placed in each child MZI (see FIG. 4B). The bias electrode Bias 90° provided in each child MZI constitute the entirety of a relative phase adjusting section. The optical signals are subjected to a phase change after the output from the child MZI (see FIG. 1A), because such relative phase adjusting section can subject the optical signals of the upper and lower arms of the child MZI to a shift change in the same direction, respectively.

Abstract: An optical modulator having a high stability is provided. In the optical modulator according to the present invention, a phase modulation by an electro-optic effect is made on an optical substrate of an electro-optic material while the setting of an operating point by a thermal-optic effect is made on a planar lightwave circuit (PLC) substrate of quartz, silicon, or the like. Such configuration can suppress the influence of thermal drift or the like because no heat is applied directly to the optical substrate of the electro-optic material. In addition, breakage and warpage of the substrate due to heat are also mitigated. Further, quartz used for the PLC has a low thermal conductivity, approximately one-fifth of that of the LN substrate (approximately 1 W/(m·K)), and therefore, a desired phase difference can be maintained with a low power consumption, and thus, the operating point becomes stabilized.

Abstract: An optical module has a structure for reducing the stress applied to a package. The optical module is structured so that an end face of a waveguide (37) of a planar lightwave circuit (30) is joined to a plurality of packages (40) storing therein optical elements so that the waveguide is optically coupled to the optical elements. The optical module includes a housing (3) storing therein a planar lightwave circuit and a plurality of packages in which an upper face of a protrusion (270) formed in the bottom section is fixed to the planar lightwave circuit (30). Each of the plurality of packages (40) is electrically connected to an electric part (22) provided in the housing (3) via flexible printed circuits (271a, 271b).

Abstract: An intake silencer of a gas turbine capable of efficient noise reduction in which a high frequency sound-absorbing splitter group composed of a plurality of sound-absorbing splitters capable of reducing highfrequency component noise and a middle/low sound-absorbing splitter group composed of a plurality of sound-absorbing splitters capable of reducing middle/low frequency component noise are disposed separately in a gas flow direction. High frequency component noise is reduced by the high frequency sound-absorbing splitter group, and middle/low frequency component noise is reduced by the middle/low sound-absorbing splitter group.

Abstract: By reducing the number of PD arrays, and by simplifying the configuration of an optical power monitor in a WDM system, a miniaturized, cost reduced optical signal monitoring apparatus, optical system or optical signal monitoring method is provided. An optical power monitor 1 has an optical switch 30 having four input ports 31, a DMUX 2 having 48 output ports, and six CSP type PD array modules 50 each including an 8-channel PD array. The output port 32 of the optical switch 30 having four switchable input ports 31 is optically connected to the input port 21 of the AWG 20. The 48 output ports 22 of the AWG 20 are each optically connected to photosensitive surfaces 53 of the individual PDs included in the CSP type PD array modules 50. The CSP type PD array modules 50 are mounted on the end face of the AWG 20.

Abstract: A large capacity HEPA filter is produced having a layered filter medium unitarily formed by an upstream non-woven fabric, which can remove 70 to 90% of 0.3 ?m particles, and a downstream non-woven fabric, which can remove 99.9% of 0.3 ?m particles or more. The layered filter medium is shaped as a mini pleat shape in a thickness direction and an entire shape in the thickness direction is a plurality of continuous Vs. Also, a dust collecting device having such a large capacity HEPA filter is produced and an air intake device for a gas turbine is provided with such a dust collecting device.

Abstract: A filter maintenance monitoring method and a filter maintained thereby are provided, by which re-use of the filter by wash is smoothly and efficiently promoted. The filter includes that loaned from a filter owner to a filter user. The filter used for a predetermined purpose and having clogging of filter cloth by filtering dust in air is recovered to be washed for re-use. History data base stored in a storage portion of a computer is renewed based on wash history of the recovered filter. Then, re-use of the filter is decided based on the renewed history data base. Changes in the filter by damages or deterioration corresponding to the wash history are automatically grasped. Thereby, an efficient filter maintenance is realized.

Abstract: A large capacity HEPA filter is produced in which a layered filter medium unitarily formed by an upstream non-woven fabric which can remove 70 to 90% of 0.3 &mgr;m particle and a downstream non-woven fabric which can remove 99.9% of 0.3 &mgr;m particle or more is provided and a shape of a layered filter medium is a minipleat shape in a thickness direction and an entire shape in the thickness direction is a plurality of continuous Vs. Also, a dust collecting device having such a large capacity HEPA filter is produced. An air intake device for a gas turbine is provided with such a dust collecting device.

Abstract: A filter maintenance monitoring method and a filter maintained thereby are provided , by which re-use of the filter by wash is smoothly and efficiently promoted. The filter includes that loaned from a filter owner to a filter user. The filter used for a predetermined purpose and having clogging of filter cloth by filtering dust in air is recovered to be washed for re-use. History data base stored in a storage portion of a computer is renewed based on wash history of the recovered filter. Then, re-use of the filter is decided based on the renewed history data base. Changes in the filter by damages or deterioration corresponding to the wash history are automatically grasped. Thereby, an efficient filter maintenance is realized.

Abstract: A gas turbine suction air filter is provided wherein, despite a large capacity, dust is easily removed by an ultrasonic washer. A gas turbine suction air filter (1) has a box-like frame member (3) and a filter cloth (5) contained in the frame member (3). The frame member (3) is made of a metal material, preferably a stainless steel. The filter cloth (5) is formed having many pleats so that many folded faces (7) are formed. No intervening member is provided between adjacent folded faces (7, 7), with only a space being arranged there. The filter cloth (5) is a non-woven fabric of a synthetic resin fiber, preferably a polypropylene fiber. While this filter (1) has a large capacity, an ultrasonic wave reaches the entire filter cloth (5) when the filter (1) is washed by an ultrasonic washer.

Abstract: A gas turbine suction air filter is provided wherein, despite a large capacity, dust is easily removed by an ultrasonic washer. A gas turbine suction air filter (1) comprises a box-like frame member (3) and a filter cloth (5) contained in the frame member (3). The frame member (3) is made of a metal material, preferably a stainless steel. The filter cloth (5) is formed having many pleats so that many folded faces (7) are formed. Between adjacent folded faces (7, 7), no intervening member is provided with only a space being arranged there. The filter cloth (5) is a non-woven fabric of a synthetic resin fiber, preferably a polypropylene fiber. While this filter (1) has a large capacity, the ultrasonic wave reaches to the entire filter cloth (5) when the filter (1) is washed by an ultrasonic washer.

Abstract: A printing plate stand and an apparatus for positioning the printing plate stand are provided. The printing plate stand is movable and supplies printing plates to a printing plate transfer apparatus. The positioning apparatus includes, at a bottom surface of the printing plate stand, a pair of fixed wheels, movable only forward and backward, free wheels, movable in multi-directions, and leg portions which are located at vicinities of the free wheels and which can project downward further than the free wheels.