Abstract: An optical wavelength conversion element includes: a wavelength conversion waveguide that has a periodic polarization reversal structure having alternately and cyclically formed domains of which polarization directions are inverted, that guides light as a fundamental wave corresponding to the periodic polarization reversal structure, and performs a wavelength conversion of the guided fundamental wave; a first clad that is made of a dielectric having a refractive index lower than that of the wavelength conversion waveguide and is provided in contact with the domains; a second clad that is made of a dielectric having a refractive index lower than that of the wavelength conversion waveguide and is provided in contact with the domains such that the second clad is opposed to the first clad film; a first conducting unit that electrically connects the domains in parallel via the first clad; and a second conducting unit that electrically connects the domains in parallel via the second clad.

Abstract: A wavelength converting element that is of a planar waveguide type, includes a plate-like nonlinear optical material, and performs a wavelength conversion on a fundamental wave of a laser beam by propagating the fundamental wave in a plurality of laser oscillation modes in a direction perpendicular to a main surface of the plate-like nonlinear optical material, the direction being perpendicular to an optical axis, wherein periods of polarization inversions of the nonlinear optical material are changed so that each of the periods has a width of a phase matching band A that includes phase matching conditions of at least two of the plurality of laser oscillation modes and so that a non-polarization-inversion region and a polarization inversion region are formed in the nonlinear optical material.

Abstract: An optical wavelength conversion element includes: a wavelength conversion waveguide that has a periodic polarization reversal structure having alternately and cyclically formed domains of which polarization directions are inverted, that guides light as a fundamental wave corresponding to the periodic polarization reversal structure, and performs a wavelength conversion of the guided fundamental wave; a first clad that is made of a dielectric having a refractive index lower than that of the wavelength conversion waveguide and is provided in contact with the domains; a second clad that is made of a dielectric having a refractive index lower than that of the wavelength conversion waveguide and is provided in contact with the domains such that the second clad is opposed to the first clad film; a first conducting unit that electrically connects the domains in parallel via the first clad; and a second conducting unit that electrically connects the domains in parallel via the second clad.

Abstract: A wavelength converting element that is of a planar waveguide type, includes a plate-like nonlinear optical material, and performs a wavelength conversion on a fundamental wave of a laser beam by propagating the fundamental wave in a plurality of laser oscillation modes in a direction perpendicular to a main surface of the plate-like nonlinear optical material, the direction being perpendicular to an optical axis, wherein periods of polarization inversions of the nonlinear optical material are changed so that each of the periods has a width of a phase matching band A that includes phase matching conditions of at least two of the plurality of laser oscillation modes and so that a non-polarization-inversion region and a polarization inversion region are formed in the nonlinear optical material.

Abstract: Provided is a photodiode array that is capable of outputting an electric signal with a large electric power and an optical microwave transmission system receiver that supplies an electric power with the aid of an optical fiber and does not require the electric power line from the external. An input modulation light is branched and input to a plurality of photodiode elements (1), electric output terminals (5) of the plurality of photodiode elements (1) are connected in parallel to each other, and a combined electric output is extracted. The electric output terminal (5) of the photodiode array configured as described above is connected to an antenna (7) without an intermediation of an amplifier circuit.

Abstract: Provided is a photodiode array that is capable of outputting an electric signal with a large electric power and an optical microwave transmission system receiver that supplies an electric power with the aid of an optical fiber and does not require the electric power line from the external. An input modulation light is branched and input to a plurality of photodiode elements (1), electric output terminals (5) of the plurality of photodiode elements (1) are connected in parallel to each other, and a combined electric output is extracted. The electric output terminal (5) of the photodiode array configured as described above is connected to an antenna (7) without an intermediation of an amplifier circuit.

Abstract: The film acoustic wave devices (12a, 12b and 12c) having the same properties are obtained by changing at least one of the followings: the length and/or the width of upper electrode (18a and 18b); the distance between the upper electrodes (18a and 18b); the length and/or the width of connecting patterns (19a and 19b); areas of bonding pads (20a and 20b); and the pattern shape for the film acoustic wave device (12a and 12b) such as the area of capacitor electrode connected electrically to the bonding pads (20a and 20b); the property variations of film acoustic wave devices (12a, 12b and 12c) caused from the positioning at wafer 11 is compensated.

Abstract: A film acoustic wave device having similar properties are obtained by changing at least one of the length and/or the width of upper electrodes; the distance between the upper electrodes; the length and/or the width of connecting patterns; the areas of bonding pads; and the pattern shape for the film acoustic wave device such as the area of capacitor electrodes electrically connected to the bonding pads. Property variations of the film acoustic wave devices caused from the positioning at a wafer is compensated for.

Abstract: There is disclosed an acoustic wave apparatus, constructed in such a manner that a surface rotated in the range of 34° to 41° from a crystal Y axis around the crystal X axis of lithium tantalate is set as the surface of a substrate, a standardized electrode thickness (h/&lgr;) obtained by standardizing a thickness h of an electrode finger constituting at least a part of an interdigital transducer by a wavelength &lgr; of a surface acoustic wave is set to the range of 0.01 to 0.05, and a duty ratio (w/p) of the electrode finger decided based on a width w and an arraying cycle p of the electrode finger is set to the value ranging from 0.6 to just below 1.0.

Abstract: An elastic wave element including a piezoelectric member, at least one electrode which is formed on the piezoelectric member, a corrosion-resistant layer which is formed on a surface of the electrode, a hydrophilic film which is formed on the corrosion-resistant layer and a dielectric film which is formed on the hydrophilic film, in which the corrosion-resistant layer is made is made of a compound of a material of the electrode and the hydrophilic film is made of a material having higher hydrophilic nature than that of the dielectric film such that the corrosion-resistant layer, the hydrophilic film and the dielectric film prevent erosion of the electrode by atmospheric water content.

Abstract: There is provided a film bulk acoustic wave device comprising: a silicon substrate 1, a dielectric film 21 including a silicon nitride 16 formed on the substrate 1 and a silicon oxide 2 on the silicon nitride 16, a bottom electrode 3 formed on the dielectric film 21, a piezoelectric film 17 formed on the bottom electrode 3, and a top electrode 5 formed on the piezoelectric film 17, wherein a via hole is formed in such a manner that the thickness direction of a part of the silicon substrate 1 which is opposite to a region including a part where the top electrode 5 exists is removed from the bottom surface of the silicon substrate 1 to a boundary surface with the silicon nitride 16.

Abstract: In an elastic wave device in which electrodes including interdigital transducers 4 and 5 made of a conductive material are formed on a piezoelectric substrate 1, a dielectric thin film 8 including silicon oxide as its main component is deposited on the interdigital transducers 4 and 5 and a reflector 9 and the thickness of this dielectric thin film 8 is appropriately set. By appropriately setting the thickness of the dielectric thin film 8, it becomes possible to obtain an elastic wave device that is not required to be hermetically sealed in a package for the sake of protecting the electrodes from minute metallic dusts and avoiding influences from the outside.

Abstract: In an elastic wave device, an electrode, which is formed in a comb-like shape and is made of conductive material having a prescribed thickness, is arranged on a substrate of a piezo-electric element containing lithium niobate as a main component. Also, in this elastic wave device, a surface of the substrate is set to a plane which is obtained by rotating a plane perpendicular to a crystal Y-axis of the lithium niobate by an angle ranging from 55 degrees to 57 degrees around a crystal x-axis of the lithium niobate, and a duty ratio (a width w of an electrode finger/an arrangement interval p of a pair of electrode fingers) of each of a plurality of electrode fingers composing the electrode is equal to or higher than 0.4 and is lower than 1.0.

Abstract: A film bulk acoustic wave device, comprising: a substrate; a bottom electrode formed on one surface of the substrate; a piezoelectric film formed on the bottom electrode; and a first top electrode formed on the piezoelectric film, further comprises a second top electrode having a larger mass load than the first top electrode, and formed on the first top electrode on the piezoelectric film when viewed from the center of the first top electrode, wherein the piezoelectric film has a high-band-cut-off-type dispersion characteristic. The cut-off frequency of a second top electrode portion piezoelectric film having a large mass load can be lower than the cut-off frequency of a first top electrode portion piezoelectric film, to thereby trap the energy of the acoustic wave in a region of the first top electrode portion side, so that good performance may be feasible.

Abstract: A film bulk acoustic wave device, comprising: a substrate; a bottom electrode formed on one surface of the substrate; a piezoelectric film formed on the bottom electrode; and a first top electrode formed on the piezoelectric film, further comprises a second top electrode having a larger mass load than the first top electrode, and formed on the first top electrode on the piezoelectric film when viewed from the center of the first top electrode, wherein the piezoelectric film has a high-band-cut-off-type dispersion characteristic.

Abstract: There is provided a film bulk acoustic wave device comprising: a silicon substrate 1, a dielectric film 21 including a silicon nitride 16 formed on the substrate 1 and a silicon oxide 2 on the silicon nitride 16, a bottom electrode 3 formed on the dielectric film 21, a piezoelectric film 17 formed on the bottom electrode 3, and a top electrode 5 formed on the piezoelectric film 17, wherein a via hole is formed in such a manner that the thickness direction of a part of the silicon substrate 1 which is opposite to a region including a part where the top electrode 5 exists is removed from the bottom surface of the silicon substrate 1 to a boundary surface with the silicon nitride 16.

Abstract: The film acoustic wave devices (12a, 12b and 12c) having the same properties are obtained by changing at least one of the followings: the length and/or the width of upper electrode (18a and 18b); the distance between the upper electrodes (18a and 18b); the length and/or the width of connecting patterns (19a and 19b); areas of bonding pads (20a and 20b); and the pattern shape for the film acoustic wave device (12a and 12b) such as the area of capacitor electrode connected electrically to the bonding pads (20a and 20b); the property variations of film acoustic wave devices (12a, 12b and 12c) caused from the positioning at wafer 11 is compensated.

Abstract: In an elastic wave device, an electrode, which is formed in a comb-like shape and is made of conductive material having a prescribed thickness, is arranged on a substrate of a piezo-electric element containing lithium niobate as a main component. Also, in this elastic wave device, a surface of the substrate is set to a plane which is obtained by rotating a plane perpendicular to a crystal Y-axis of the lithium niobate by an angle ranging from 55 degrees to 57 degrees around a crystal x-axis of the lithium niobate, and a duty ratio (a width w of an electrode finger/an arrangement interval p of a pair of electrode fingers) of each of a plurality of electrode fingers composing the electrode is equal to or higher than 0.4 and is lower than 1.0.

Abstract: A detecting device for detecting a physical quantity of an object, which includes a transmission signals generating device for generating first and second transmission signals of different frequencies, an ultrasonic wave transmission device that is excited by the first and the second transmission signal, for transmitting ultrasonic pulses corresponding to the first and the second transmission signal to an object, and a signal processing device for carrying out a signal processing process on the first and the second echo. The signal processing process is such that it detects phases of the first and second echo corresponding to the first and second transmission signal, which are received by the ultrasonic wave receiving device. An indeterminacy integer times as large as 2.pi.

Abstract: Embodiments of the present invention provide a small and well-characterized bulk acoustic wave device by fabricating a filter having a wide band width or a resonator having a wide oscillation frequency range together with a semiconductor circuit. In embodiments of the present invention, a bulk acoustic wave device comprises a semiconductor substrate having a dielectric substance layer thereon, the dielectric substance layer has a ground conductor layer thereon, the ground conductor layer has a piezoelectric ceramic thin film thereon and the piezoelectric ceramic thin film has a conductive electrode pattern thereon. The thickness of the piezoelectric ceramic thin film is more than ten times the thickness of the ground conductor layer, and the wave number of acoustic waves that propagate in a direction parallel to a surface of the piezoelectric ceramic thin film multiplied by the thickness of the piezoelectric ceramic thin film is less than 2.