Abstract: In a wavelength selection element employed in an optically variable filter array apparatus, pixels in a line form are placed into a light reflection state so that wavelength-scanned light can be incident on the optically variable filter array apparatus. On the basis of the wavelength of scanned reflection light and the location of the pixel in a light reflection state at a timing of acquisition of output, the relationship between the x coordinate of the wavelength selection element and wavelength is determined. This makes it possible to achieve calibration of the optically variable filter array apparatus capable of selection of a desired wavelength with respect to a desired channel from multi-channel WDM light.

Abstract: In an optically variable filter array apparatus, WDM-signal light beams of m channels ranging in wavelength from ?1 to ?n from optical fibers 11-1 to 11-m enter wavelength dispersion element 17 through concave mirror 16. Wavelength dispersion element disperses incident light beams in different directions according to their wavelengths and direct them to a concave mirror 18. In concave mirror, light beams of different channels are turned into strip-like parallel light beams and developed over xy plane according to channel and wavelength. Wavelength selection element 19 has pixels arranged in lattice pattern, for bringing a pixel at a position corresponding to to-be-selected channel and wavelength into a reflective state. Light beams reflected from wavelength selection element pass through the same path to exit from optical fibers 15-1 to 15-m. By changing reflection characteristics of wavelength selection element on a pixel-by-pixel basis, desired wavelengths of given WDM light can be selected.

Abstract: In an optically variable filter array apparatus, WDM-signal light beams of m channels ranging in wavelength from ?1 to ?n from optical fibers 11-1 to 11-m enter wavelength dispersion element 17. Wavelength dispersion element 17 disperses incident light beams in different directions according to their wavelengths. In lens 18, light beams of different channels are turned into strip-like parallel light beams and developed over xy plane according to channel and wavelength. Wavelength selection element 19 has pixels arranged in lattice pattern, for bringing a pixel at a position corresponding to to-be-selected channel and wavelength into a reflective state. Light beams reflected from wavelength selection element 19 pass through the same path to exit from optical fibers 15-1 to 15-m. By changing reflection characteristics of wavelength selection element 19 on a pixel-by-pixel basis, characteristics of optical filter can be varied, so that desired wavelengths of given WDM light can be selected.

Abstract: A wavelength selective switch device includes an incidence part where wavelength multiplexed light made of light of a plurality of wavelengths enters, an exit part that includes a plurality of fiber that outputs light of a wavelength selected from a signal in which wavelength multiplexed light that entered from the incidence part enters, a polarization diversity part that separates incidence light that entered the incidence part according to polarization components of the incidence light to make first and second optical beams, a wavelength dispersion and synthesis element that spatially disperses incidence light according to a wavelength of the incidence light and multiplexes the spatially dispersed reflected light according to the wavelength, and a wavelength dispersion and synthesis element that spatially disperses incidence light according to a wavelength of the incidence light and multiplexes the spatially dispersed reflected light according to the wavelength.

Abstract: Light from an optical fiber is incident on a frequency dispersion element. The frequency dispersion element disperses the incident light into light beams in different directions according to their frequencies and directs the dispersed light beams to a lens. The lens develops the incident light beams over an xy plane according to their frequencies in a strip-like form. A frequency selective element has pixels arranged in a frequency dispersion direction and brings pixels located at positions corresponding to the frequency to be selected into a reflective state. A light beam selected by the frequency selective element is emitted from an optical fiber through the same path. By changing reflection characteristics of the frequency selective element according to each pixel, optical filter characteristics can be desirably changed so as to achieve change of passband width and frequency shift.

Abstract: In a wavelength selective optical switch device that disperses a WDM light beam according to their wavelengths. Dispersed light beams is applied to a wavelength selecting element. Incident light beams are separately reflected in different directions according to their wavelengths by use of the multi-level optical phased array. In the optical phased array, even when the number of multi levels is small, by setting the maximum phase shift amount of the phased array to be at least 1.5 ? and less than 2.0 ?, wavelength dependence is reduced, thereby reducing crosstalk. In this manner, the wavelength dependence, in turn, crosstalk can be reduced.

Abstract: A method for controlling a characteristic of a variable optical filter including a frequency selecting element includes changing a driving voltage for a specific pixel of the frequency selecting element continuously to produce an amount of change in a frequency that is passed through that pixel, changing a driving voltage value for a specific pixel of the frequency selecting element continuously to produce an attenuation value for a beam that is passed through that pixel, calculating, from a relationship between the driving voltage and a frequency characteristic and between the driving voltage and amount of attenuation, a function that indicates an approximated curve of no less than a second order and no more than a sixth order for expressing a relationship between a transmissivity and a frequency, and controlling the characteristic through driving a controlled pixel of the frequency selecting element based on the function.

Abstract: To provide a treatment agent for asbestos, which has a less influence on human body, the construction and the surrounding environment and can render the asbestos harmless evenly up to the inside of the bulky covering materials, which cover the wall, or the slate materials, and a treatment method of the asbestos using the same. A treatment agent for asbestos, which contains phosphoric acid of 0.5 through 3.0% by weight, hydrogen peroxide of 1 through 20% by weight, alcohol of 0.5 through 20% by weight and pure water and a treatment method of the asbestos using the same are described.

Abstract: A light is incident on a refractive diffraction grating 13, and is distributed for each of wavelengths at different angles to be outputted. A lens 14 converts the distributed lights into belt-shaped lights, and the belt-shaped lights are incident on a mirror substrate 15 having selective reflection regions 17-1 to 17-x. By moving the mirror substrate 15 toward a direction different from a distribution direction of the belt-shaped lights, only the light of any one of wavelengths is reflected. Then, the light returning to the refractive diffraction grating 13 is reflected to an incident direction of the original light. Accordingly, a tunable filter which is able to select a light of an arbitrary wavelength by moving the mirror substrate 15 can be realized.

Abstract: A tunable light source 10 for varying emission wavelength periodically and an optical interferometer are used. A reflector is disposed at a measurement position, a light interference signal is A/D converted at a regular time interval, and data numbers at timing giving peak and bottom are calculated according to a least-squares method. Based on this, an approximate equation is calculated according to polynomial approximation and a sequence including the number of exponentiation of 2 and converting the data number at a regular frequency interval is calculated. Then, by disposing a measured target at the measurement position, calculating the necessary number of pieces of data for FFT from measured data at each timing according to straight-line approximation and Fourier transforming a light beat signal obtained by an optical interferometer at regular frequency interval, a tomogram having high resolution and high sensitivity can be acquired.

Abstract: An actuator that can be driven at a reduced voltage and manufactured with ease, and a method for manufacturing the same are provided. The actuator includes second supporting portions 31 and 32 secured to a supporting substrate 4 through a spacer, fixed portions 33 and 34 secured to the supporting substrate 4 with no intervention of the spacer, fixed comb electrodes 331 and 341 integrally formed the fixed portions 33 and 34 and meshing with movable comb electrodes 211 and 212 in a spaced-apart relationship, and bridge portions 35 and 36 for connecting the fixed portions 33 and 34 to the second supporting portions 31 and 32.

Abstract: A light from an optical fiber is incident on a dispersive element via an optical circulator and an optical fiber. The dispersive element disperses the incident light toward directions different depending on wavelength to apply the dispersed lights to a lens. The lens focuses the lights at positions different for each wavelength of the light. The patterning plate has desired reflection characteristics. The lights reflected on the patterning plate are multiplexed by the dispersive element through the identical path to be emitted from an optical fiber via the optical circulator. Desired characteristics can be obtained by arbitrarily changing a pattern with reflection characteristics of the patterning plate. In addition, a characteristic of the optical filter can be changed by moving the patterning plate.

Abstract: An actuator that can be driven at a reduced voltage and manufactured with ease, and a method for manufacturing the same are provided. The actuator includes second supporting portions 31 and 32 secured to a supporting substrate 4 through a spacer, fixed portions 33 and 34 secured to the supporting substrate 4 with no intervention of the spacer, fixed comb electrodes 331 and 341 integrally formed the fixed portions 33 and 34 and meshing with movable comb electrodes 211 and 212 in a spaced-apart relationship, and bridge portions 35 and 36 for connecting the fixed portions 33 and 34 to the second supporting portions 31 and 32.

Abstract: A surface emission laser light source is used as a tunable laser light source. Since the surface emission laser light source can realize a broad frequency scanning range at a high speed and in the single mode, a coherent length is longer than that of a multi mode light source. For this reason, when a tomography image is calculated by executing the Fourier transform for an output obtained from an interference optical device, measuring depth can be deepened.

Abstract: An optical fiber loop has a gain medium having a gain at an oscillation wavelength and optical circulators 13 and 14. Collimate lenses 22 and 24 enlarge light bean taken from the optical circulators 13 and 14. A polygon mirror 25 is provided on the light axis, and is rotated. A diffraction grating 27 is provided at the receiving position of the light reflected by the polygon mirror 25, and is of a Littrow configuration which reflects the light in the same direction as the incident light. A selected wavelength changes according to an incident angle to the diffraction grating 27, resulting in increase of selectivity owing to twice incident, thereby permitting to change an oscillation wavelength with narrow band even when changing the selected wavelength by rotating the polygon mirror 25 at high speed.

Abstract: An optical tunable filter has a fixed substrate having a first recess formed therein and a movable substrate bonded to the fixed substrate. The movable substrate includes a movable portion having an opening formed at a location facing the first recess and a support portion for supporting the movable portion so that the movable portion can be displaced. The optical tunable filter also has a light-transmittable substrate bonded to the movable portion, a fixed reflection film formed on a bottom of the first recess, and a movable reflection film formed on a surface of the light-transmittable substrate. The optical tunable filter includes an interference gap formed between the fixed reflection film and the movable reflection film. The optical tunable filter also includes an actuator operable to displace the movable portion relative to the fixed substrate.

Abstract: An optical pulse evaluation device and an in-service optical pulse evaluation device is disclosed which are capable of characteristics evaluation of an optical pulse itself or a sample launched therein in a relatively high bit-rate region. The optical pulse evaluation device evaluates a pulse waveform expressing an optical intensity of the optical pulse, an instantaneous frequency of the optical pulse, or a modulated light prepared by modulating the optical pulse in a light source end. The optical pulse evaluation device also observes a waveform change after a known optical pulse is passed through a device such as an optical fiber to evaluate a waveform deterioration or a compensation behavior caused by the device. The in-service optical pulse evaluation device is capable of measuring a wavelength dispersion in an optical communication.

Abstract: PROBLEM TO BE SOLVED: to realize a wide bandwidth light source capable of a stable operation providing a less spectrum variation. SOLUTION: Optical pulses 202 outputted by this optical pulse-generating device 201 are split by optical coupler 210. The one of split optical pulses is inputted in white light-emitting device 204 to emit the white light having the wide bandwidth. The other split is inputted in optical band pass filter 212 in operation-stabilizing circuit 207. Optical detector 213 detects a signal level of a specific wavelength and input in feedback circuit 215 to generate first and second feedback signals 205 and 206. Ring resonator fiber laser 208 uses any one of them and controls a rotation angle of the waveplate to realize stabilization of the output.

Abstract: An optical fiber loop has a gain medium having a gain at an oscillation wavelength and optical circulators 13 and 14. Collimate lenses 22 and 24 enlarge light bean taken from the optical circulators 13 and 14. A polygon mirror 25 is provided on the light axis, and is rotated. A diffraction grating 27 is provided at the receiving position of the light reflected by the polygon mirror 25, and is of a Littrow configuration which reflects the light in the same direction as the incident light. A selected wavelength changes according to an incident angle to the diffraction grating 27, resulting in increase of selectivity owing to twice incident, thereby permitting to change an oscillation wavelength with narrow band even when changing the selected wavelength by rotating the polygon mirror 25 at high speed.

Abstract: A loop is formed with an optical fiber by providing a gain medium having a gain with respect to an oscillation wavelength. Light retrieved by the optical circulator 13 from the optical fiber loop is enlarged and projected to a mirror 23. A diffraction grating 25 is provided with respect to the light reflected in the mirror. The diffraction grating 25 has a Littrow arrangemnt wherein the light is reflected in a same direction as incident light. A selected wavelength is changed in accordance with an incident angle with respect to the diffraction grating 25. Therefore, when the mirror 23 is rotated so as to change the selected wavelength, the oscillation wavelength can be changed at high speed.