Abstract: In a diffraction grating device (1), index modulations are formed along the longitudinal direction of an optical fiber (10) serving as an optical waveguide. The optical fiber (10) has a core region (11), an inner cladding region (12), and an outer cladding region (13) sequentially from the optical axis center. Index modulations are formed in both the core region (11) and the inner cladding region (12) of the optical fiber (10) in each of a plurality of regions A1 to AN (N is an integer; N?2) separated from each other along the longitudinal direction of the optical fiber (10). In the diffraction grating device (1), regions An (n=1 to N) in which index modulations are formed in both the core region (11) and the inner cladding region (12) and regions Bn (n=1 to N?1) in which no index modulations are formed alternately exist along the longitudinal direction.

Abstract: The present invention relates to a method for treating liquids used in inkjet recording comprising, providing a first printing liquid and a second printing liquid that is capable of reacting with the first printing liquid to cause coagulation and thickening if mixed with the first printing liquid, and exposing the first and second printing liquids to each other to form a mixture, wherein when the mixture includes a coagulation-thickening preventing agent which prevents the reaction of the printing liquids.

Abstract: In a method of making a diffraction grating device, an optical waveguide is irradiated, by way of a phase grating mask, with refractive index modulation inducing light so as to form a diffraction grating in the predetermined region. This method comprises (1) a step of measuring a diffraction efficiency distribution of the phase grating mask; and (2) a step of longitudinally scanning the optical waveguide with the refractive index modulation inducing light by way of the phase grating mask and irradiating the optical waveguide with the refractive index modulation inducing light so as to modulate a refractive index of the predetermined region. Upon scanning with the refractive index modulation inducing light, longitudinal relative positions of the phase grating mask and optical waveguide are changed according to the diffraction efficiency distribution of the phase grating mask.

Abstract: An ink jet recording ink is provided containing water, a pigment that is self-dispersible in water, a water-soluble organic solvent, and a nonionic polymer of which the amount is preferably in a range of about 5% by mass to about 200% by mass relative to the total mass of the pigments. The nonionic polymer is preferably selected from a group consisting of polyvinyl alcohol, polyvinyl pyrrolidone, polyacrylamide, poly N-vinyl acetamide, and the like. The absolute value of zeta potential of the ink is preferably in the range of about 5 mV to about 30 mV.

Abstract: A liquid composition containing at least water, a photopolymerization initiator, a water-soluble organic solvent and a polymerizable compound that can cause a polymerization reaction due to the photo polymerizing initiator, wherein the polymerizable compound is contained two or more kinds, the glass transition temperature (Tg) of at least one kind of the polymerizable compound being 50° C. or more, and the glass transition temperature (Tg) of at least one kind thereof being 10° C. or less, an ink set for ink jet, and a recording method and a recording apparatus using the same.

Abstract: The present invention relates to a method and apparatus which make it possible to manufacture an optical waveguide type diffraction grating device achieving desired optical characteristics easily. In the present method, the optical fiber is irradiated as refractive index change inducing light outputted from a light source through a phase grating mask after passing through a shutter, an optical system, and a mirror. The mirror is moved in the direction of a z-axis to scan the irradiating position of the refractive index change inducing light on the optical fiber plural times. Every scan among the plurality of scans of the irradiating position, the phase grating mask is relatively displaced along the z-axis the direction opposite to each other from a reference relative position of the phase grating mask relative to the optical fiber.

Abstract: An ink set for ink jet recording including plural color inks including a black ink, the ink set including water, a water-soluble organic solvent and colorants. At least one of the color inks having a hue other than black is a specified color ink containing a compound for coagulating a colorant contained in the black ink, at least one of other color inks has a function for improving coagulability between the colorant contained in the black ink and the compound contained in the specified color ink, and the drying time of the black ink on a plain paper sheet is less than 5 seconds.

Abstract: The present invention provides an ink set for ink jet recording comprising: an ink which contains: water; a colorant; a water-soluble organic solvent; polyvalent metal ions; and compound (A) which is intrinsically capable of substantially inactivating the polyvalent metal ions, and a liquid composition is of a pH in which the polyvalent metal ions in the ink can be substantially activated. The pH of the ink is within a range in which compound (A) keeps the polyvalent metal ions substantially in an inactive state. The invention also provides an ink jet recording method which uses such an ink set.

Abstract: A recording paper containing pulp fibers, a filler, and an amine, wherein the amine is a primary, secondary, or tertiary amine represented by the following Formula (&agr;). In the following Formula (&agr;), at least one of substituents represented by R1, R2, and R3 is a hydrocarbon group containing a hydroxyl group. In addition, also provided are an ink jet recording method including recording images on the recording paper; an ink jet recording device equipped with a recording head for ejecting ink onto the recording paper; an electrophotographic recording method including fusing toner images on the recording paper surface; and an electrophotographic recording device including a fusing means that fuses a toner image on the recording paper surface.

Abstract: In this diffraction grating device manufacturing method, refractive-index-change-inducing light of a wavelength that induces a change in refractive index is irradiated onto an optical waveguide, thus forming a diffraction grating through refractive index modulation along the longitudinal direction of the optical waveguide. At this time, the position of irradiation of the refractive-index-change-inducing light onto the optical waveguide is swung in a direction perpendicular to the longitudinal direction of the optical waveguide.

Abstract: A data carrier which can be read from and written to in a non-contact state is embedded in the bottom of tableware, and in which data such as price, etc. are written. When a customer selects dishes or drinks and places the dishes or drinks on a tray, all the data are simultaneously read from the data carriers on the tray, and the total amount of charge is calculated.

Abstract: Refractive index change inducing light UV outputted from a light source passes a shutter and an optical system, and then is reflected by a mirror, so as to irradiate an optical fiber by way of a phase grating mask. A diffracting action of the phase grating mask generates a (+)first-order light component and a (−)first-order light component, which interfere with each other, thereby generating interference fringes with a fringe interval &Lgr;. As the mirror moves along the z axis, an irradiation position at which the optical fiber is irradiated with the refractive index change inducing light UV by way of the phase grating mask is scanned. While moving the mirror upon irradiation with the refractive index change inducing light UV, the phase grating mask is vibrated along the z axis under the action of a piezoelectric device. The phase or period of vibration varies from scan to scan.

Abstract: The present invention relates a method of easily fabricating a grating device having a desired reflection characteristic, and the like. In this fabrication method, the phase grating mask is relatively shifted along the longitudinal direction of the optical waveguide by a distance of one half of the grating period of the phase grating mask during the refractive index change inducing light is irradiated on the optical waveguide through the phase grating mask.

Abstract: The present invention relates to an optical waveguide type grating element and others in structure for decreasing absolute values of chromatic dispersion occurring in selective reflection of each of signal channels in a reflection band. The optical waveguide type grating element is provided with an optical waveguide in which signal light containing a plurality of signal channels spaced at a channel spacing &lgr;i propagates, and a grating which is an index modulation formed over a predetermined range of the optical waveguide. Particularly, the optical waveguide type grating element has a transmittance of −20 dB or less for each of the signal channels in the reflection band, and has a reflectance of −20 dB or less for each of signal channels outside the reflection band. Furthermore, a deviation of a group delay time of each of the signal channels in the reflection band, which is caused by reflection in the grating, is 10 ps or less in a wavelength range of (&lgr;CH−&lgr;i×0.

Abstract: In a method of making a diffraction grating device, an optical waveguide is irradiated, by way of a phase grating mask, with refractive index modulation inducing light so as to form a diffraction grating in the predetermined region. This method comprises (1) a step of measuring a diffraction efficiency distribution of the phase grating mask; and (2) a step of longitudinally scanning the optical waveguide with the refractive index modulation inducing light by way of the phase grating mask and irradiating the optical waveguide with the refractive index modulation inducing light so as to modulate a refractive index of the predetermined region. Upon scanning with the refractive index modulation inducing light, longitudinal relative positions of the phase grating mask and optical waveguide are changed according to the diffraction efficiency distribution of the phase grating mask.

Abstract: An ink jet recording liquid of high optical density, good rub resistance, and excellent feathering and long-term preservation stability when the liquid is used for printing on plain paper is used in an ink jet recording method. In the ink jet recording liquid which contains a pigment, water soluble organic solvent, and water as the essential components, and additionally containing water soluble resin and/or surfactant, 1) the temporal change rate of dynamic contact angle on plain paper is in a range from 0.5 to 3.5 degrees/second, 2) the number average particle diameter in the ink jet recording liquid is in a range from 15 to 100 nm, and 3) the volume average particle diameter in the ink jet recording liquid is in a range from 30 to 200 nm. The above-mentioned ink jet recording liquid is printed by means of ink jet recording.

Abstract: In this diffraction grating device manufacturing method, refractive-index-change-inducing light of a wavelength that induces a change in refractive index is irradiated onto an optical waveguide, thus forming a diffraction grating through refractive index modulation along the longitudinal direction of the optical waveguide. At this time, the position of irradiation of the refractive-index-change-inducing light onto the optical waveguide is swung in a direction perpendicular to the longitudinal direction of the optical waveguide.

Abstract: The present invention relates to a method of making a diffraction grating device, in which an optical waveguide is irradiated, by way of a phase grating, with light capable of inducing a refractive index modulation in an optical waveguide region of the optical waveguide so as to form a diffraction grating in the optical waveguide region. In the present invention, when modulating the refractive index of the optical waveguide region of an optical fiber, the intensity of refractive index modulation inducing light emitted from a laser light source so as to irradiate the phase grating is adjusted according to individual positions on the phase grating. Alternatively, the scanning speed of a mirror scanned by a stage is adjusted according to the individual positions on the phase grating. Here, the amount of irradiation of refractive index modulation inducing light at each position on the phase grating is adjusted so as to cancel the diffraction efficiency distribution of phase grating.

Abstract: The present invention relates to an optical fiber having a sufficient strength, in which not only a core region but also a cladding region contains GeO2, and an optical component including the same. The optical fiber has an outer diameter D; and comprises a core region, a first cladding region surrounding the core region, and a second cladding region surrounding the first cladding region. The core region is a glass region mainly composed of a silica glass material with a GeO2 content of 1 wt % or more. The first cladding region is a glass region, mainly composed of a silica glass material with a GeO2 content of 1 wt % or more, having an outer diameter of 0.80D or more but 0.98D or less. The second cladding region is a glass region mainly composed of a silica glass material with a GeO2 content of less than 0.2 wt %.

Abstract: The method of making a diffraction grating device in accordance with the present invention comprises the steps of preparing an optical waveguide having an optical waveguide region doped with an additive adapted to generate a refractive index change upon irradiation with refractive index change inducing light having a predetermined wavelength, and a phase grating having a predetermined projection and depression pattern; separating the optical waveguide and the phase grating from each other by a distance yielding a predetermined optical path difference between zero-order transmitted light and second-order diffracted light of the refractive index change inducing light such that a modulation intensity of interference light between the zero-order transmitted light and second-order diffracted light becomes 85% or less of that obtained when no optical path difference exists between the zero-order transmitted light and second-order diffracted light; and making the refractive index change inducing light incident on th