Abstract: An optical device includes: an optical component; a case air-sealed, and made of metal, the optical component being secured within the case; and a lens provided within the case, and positionally adjusted in consideration of a deformation of the case air-sealed, light emitted from the optical component passing through the lens or light traveling to the optical component passing through the lens.

Abstract: An optical device includes: an optical component; a case air-sealed, and made of metal, the optical component being secured within the case; and a lens provided within the case, and positionally adjusted in consideration of a deformation of the case air-sealed, light emitted from the optical component passing through the lens or light traveling to the optical component passing through the lens.

Abstract: An optical switch includes an input port into which a multiplexed optical signal is input; a dispersing unit that, according to wavelength, disperses the multiplexed optical signal into a plurality of optical signals that are each dispersed in a unique direction; a converging unit that converges the dispersed optical signals; plural mirrors that are arrayed forming a single row in a plane and reflecting the converged optical signals, respectively; and plural output ports through which the reflected optical signals are output. Each of the mirrors has a concave reflective surface that is in the plane and of a predetermined curvature about an axis parallel to the plane.

Abstract: An optical switch includes an input port into which a multiplexed optical signal is input; a dispersing unit that, according to wavelength, disperses the multiplexed optical signal into a plurality of optical signals that are each dispersed in a unique direction; a converging unit that converges the dispersed optical signals; plural mirrors that are arrayed forming a single row in a plane and reflecting the converged optical signals, respectively; and plural output ports through which the reflected optical signals are output. Each of the mirrors has a concave reflective surface that is in the plane and of a predetermined curvature about an axis parallel to the plane.

Abstract: A housing 20 is equipped for supporting, from a side, a platform of a wavelength selection device comprising an input/output port 10, a collimator 11, an expanding optical system 12, a spectroscopic element, a collecting optical system 14 and a micro electro mechanical system (MEMS) mirror array 15. Because the above noted optical member is supported from the side only, influences of a thermal expansion is limited to the height direction of the optical member and the optical axis direction. By these aspects, the influence of thermal expansion is limited to a two-dimensional from a common three-dimensional, thereby enabling a design of a countermeasure to an influence of a thermal expansion. Also, the support from the side does not create a dead space thereby making the wavelength selection device compact.

Abstract: A wavelength selective optical switch of the present invention separates a WDM light emitted from an input port of an input and output optical system, according to wavelengths, by a diffraction grating, and thereafter, condenses the lights of respective wavelengths on MEMS mirrors respectively corresponding to the respective wavelengths, in a mirror array, to reflect them by a condenser optical system, to thereby switch optical paths for the respective lights. The condenser optical system is configured by combining a plurality of lenses whose focal distances are different from each other, and positions in an optical axis direction of the lenses are adjustable by a slide mechanism. Thus, despite an error in the focal distances of the condenser lenses, in a mounting angle of a spectral element or the like, a beam pitch at the condensing positions of the lights of respective wavelengths can be coincident with a mirror pitch in the mirror array.

Abstract: A housing 20 is equipped for supporting, from a side, a platform of a wavelength selection device comprising an input/output port 10, a collimator 11, an expanding optical system 12, a spectroscopic element, a collecting optical system 14 and a micro electro mechanical system (MEMS) mirror array 15. Because the above noted optical member is supported from the side only, influences of a thermal expansion is limited to the height direction of the optical member and the optical axis direction. By these aspects, the influence of thermal expansion is limited to a two-dimensional from a common three-dimensional, thereby enabling a design of a countermeasure to an influence of a thermal expansion. Also, the support from the side does not create a dead space thereby making the wavelength selection device compact.

Abstract: A wavelength division element includes a first filter and a second filter. The first filter has incident angle-to-transmission wavelength characteristics and separates multiplexed lights in a plurality of wavelength bands into first lights that are in a first wavelength band and first reflected lights. The first filter allows the first lights to pass through in a first direction and reflects the first reflected lights in a second direction. The second filter is located in the second direction and separates the first reflected lights into second lights that are in a second wavelength band and second reflected lights. The second filter allows the second lights to pass through in a third direction and reflects the second reflected lights in a fourth direction.

Abstract: A wavelength selective optical switch of the present invention separates a WDM light emitted from an input port of an input and output optical system, according to wavelengths, by a diffraction grating, and thereafter, condenses the lights of respective wavelengths on MEMS mirrors respectively corresponding to the respective wavelengths, in a mirror array, to reflect them by a condenser optical system, to thereby switch optical paths for the respective lights. The condenser optical system is configured by combining a plurality of lenses whose focal distances are different from each other, and positions in an optical axis direction of the lenses are adjustable by a slide mechanism. Thus, despite an error in the focal distances of the condenser lenses, in a mounting angle of a spectral element or the like, a beam pitch at the condensing positions of the lights of respective wavelengths can be coincident with a mirror pitch in the mirror array.

Abstract: Light incident on an input optical fiber is separated into p-polarized light and s-polarized light by a birefringent crystal. A voltage to be applied to a liquid crystal element having electrodes associated with the ray axes of the polarized light waves is controlled in order to convert the p-polarized light into s-polarized so that both the polarized light waves will be s-polarized light. A polarized-wave separation film transmits p-polarized light and reflects s-polarized light. When both the polarized light waves propagated through the liquid crystal element are s-polarized light, the light reflected from the polarized-wave separation film is reflected from a total-reflection film, and reflected again from the polarized-wave separation film. The resultant light falls on the birefringent crystal again via the liquid crystal element, and is restored to non-polarized light by the birefringent crystal. The non-polarized light then falls on a first output optical fiber.

Abstract: A variable optical attenuator is constituted of input/output optical systems, a birefringent member provided at output sides of the input/output optical systems, a liquid-crystal member capable of individually varying polarizing states of input beams exiting the birefringent member, and a reflection member which reflects light passing through the liquid-crystal member, to thereby cause the light to return to an output lens of the input/output optical systems by way of the liquid-crystal member and the birefringent member. Thus, there can be provided a variable optical attenuator which is more compact and less expensive than a related-art variable optical attenuator.

Abstract: Light incident on an input optical fiber is separated into p-polarized light and s-polarized light by a birefringent crystal. A voltage to be applied to a liquid crystal element having electrodes associated with the ray axes of the polarized light waves is controlled in order to convert the p-polarized light into s-polarized so that both the polarized light waves will be s-polarized light. Otherwise, the s-polarized light is converted into p-polarized light so that both the polarized light waves will be p-polarized light. A polarized-wave separation film located behind the liquid crystal element transmits p-polarized light and reflects s-polarized light. When both the polarized light waves propagated through the liquid crystal element are s-polarized light, the light reflected from the polarized-wave separation film is reflected from a total-reflection film, and reflected again from the polarized-wave separation film.

Abstract: A wavelength division element includes a first filter and a second filter. The first filter has incident angle-to-transmission wavelength characteristics and separates multiplexed lights in a plurality of wavelength bands into first lights that are in a first wavelength band and first reflected lights. The first filter allows the first lights to pass through in a first direction and reflects the first reflected lights in a second direction. The second filter is located in the second direction and separates the first reflected lights into second lights that are in a second wavelength band and second reflected lights. The second filter allows the second lights to pass through in a third direction and reflects the second reflected lights in a fourth direction.

Abstract: There provided a small low-cost optical monitor device. In this optical monitor device, input fibers and output fibers are arranged in an array on one side, first lenses are arranged in an array on the optic axes of input optical signals outputted from the input fibers, and second lenses are arranged in an array on the optic axes of output optical signals inputted to the output fibers. Input optical signals is inputted to a coupler film via the first lenses and optical signals which pass through the coupler film will be detected by front incidence type PD elements. On the other hand, output optical signals reflected from the coupler film are inputted to the second lenses separate from the first lenses, from which the input optical signals were outputted, and are coupled to the corresponding output fibers. As a result, a reflection and loop back structure is realized. In this reflection and loop back structure, a plurality of input optical signals are reflected accurately by a coupler film and are outputted.

Abstract: A variable optical attenuator is constituted of input/output optical systems, a birefringent member provided at output sides of the input/output optical systems, a liquid-crystal member capable of individually varying polarizing states of input beams exiting the birefringent member, and a reflection member which reflects light passing through the liquid-crystal member, to thereby cause the light to return to an output lens of the input/output optical systems by way of the liquid-crystal member and the birefringent member. Thus, there can be provided a variable optical attenuator which is more compact and less expensive than a related-art variable optical attenuator.

Abstract: A laser diode module including a laser diode assembly having a laser diode and a holder, a lens-fiber assembly having a lens and an optical fiber fixed in a given positional relationship, and a sleeve. The lens-fiber assembly includes a casing having a first hole and a second hole offset from the first hole. The lens is inserted and fixed in the first hole, and a ferrule in which the optical fiber is embedded is press-fitted with the second hole. The ferrule has a slant polished first end and a second end projecting from an end surface of the casing by a given distance. The lens and the ferrule are fixed in the casing so that a given distance is defined between the lens and the first end of the ferrule.

Abstract: An optical receptacle module includes an optical module unit including therein an optical device and carrying a sleeve, a ferrule holder fitted into the sleeve and holding therein a ferrule, a frame member mounted on the ferrule holder, and an adapter unit mounted on the frame unit and accepting an external optical plug, wherein the ferrule holder having an engagement part for engagement with the frame at a location away from the optical device with respect to an engagement part of the frame member used for engagement with the adapter unit.