Abstract: Provided is a device for removing coating on an optical fiber. The device has a cutting depth limiting surface disposed on a receiver body and a cutting blade attached between a pusher body and a fixing block. The cutting blade is made from plastics and has a specified bending elasticity. An optical fiber is inserted between the cutting blade and the limiting surface. During operation, the cutting blade cuts into a covering on the optical fiber. A high precision in arranging the cutting blade is not required.

Abstract: The conventional EDFA has such problems that it is very costly since it requires an external high-energy laser diode and an optical coupling means for optically coupling the pumping light given from the laser diode, and that it must have a long length for obtaining a desired amplification degree. A constitution having an optical waveguide and an pumping light source integrated for solving the problems is also proposed, but it also has a problem in view of downsizing. This invention proposes a waveguide optical amplifier 1, in which a surface light emission source 3 for pumping driven electrically is provided adjacently to and integrally with an optical waveguide 2 doped with a light-emitting species, in the longitudinal direction of the optical waveguide.

Abstract: An electrostatic comb drive actuator, characterized in that plural outer suspended elastic beams 2a and 2b are disposed in parallel to and outside plural inner suspended elastic beams 1a and 1b disposed in parallel to each other; the ends of the inner suspended elastic beams and the outer suspended elastic beams on both sides are connected with end connecting beams 3a and 3b; the outer suspended elastic beams are supported at their centers on a board 5; the inner suspended elastic beams are connected with each other at their centers by means of a working section 6; a movable comb electrode 7 is supported on the working section; and a fixed comb electrode 8 is supported on the board.

Abstract: Provided is a device for removing coating on an optical fiber. The device has a cutting depth limiting surface disposed on a receiver body and a cutting blade attached between a pusher body and a fixing block. The cutting blade is made from plastics and has a specified bending elasticity. An optical fiber is inserted between the cutting blade and the limiting surface. During operation, the cutting blade cuts into a covering on the optical fiber.

Abstract: Provided is a device for removing coating on an optical fiber. The device has a cutting depth limiting surface disposed on a receiver body and a cutting blade attached between a pusher body and a fixing block. The cutting blade is made from plastics and has a specified bending elasticity. An optical fiber is inserted between the cutting blade and the limiting surface. During operation, the cutting blade cuts into a covering on the optical fiber. A high precision in arranging the cutting blade is not required.

Abstract: An optical attenuator which provides almost the same degree of attenuation even when the difference in wavelength of two different kinds of input optical signals is small. Another optical attenuator is provided with a dopant concentration in a technically realizable range which increases the difference in optical attenuation of two different kinds of input optical signals. Almost the same degree of attenuation may be obtained even when the difference between wavelengths is small by canceling the wavelength dependency of attenuation of the dopant by raising the refractive index of an axially central portion of the core as compared to that of the peripheral portion of the core and by taking into account the type and area of the dopant and the ratio of the difference &Dgr;2 between the refractive indexes of the cladding and the axial portion of the core and the difference &Dgr;1 between the refractive index of the cladding and the refractive index of the peripheral portion, i.e., &Dgr;1/&Dgr;2.

Abstract: Abnormal losses outside a reflection band attributable to a mismatch of core field diameters are suppressed. A photo-sensitive fiber comprising a core 1 and a cladding having a cladding inner layer and a cladding outer layer formed in this order around the core, in which at least the core is photo-sensitive to form a grating. The core and cladding inner layer include a photo-sensitive dopant for increasing the refractive index. The core additionally includes a first non-photo-sensitive dopant for increasing the refractive index and the cladding inner layer additionally includes a second non-photo-sensitive dopant for creasing the refractive index.

Abstract: Disclosed are optical fibers for optical attenuation comprising a core and a cladding, wherein the cladding comprises two or more parts different from each other in their refractive indices and/or the attenuating dopant existence. By using the optical fibers for optical attenuation of the present invention, an optical attenuator which can effectively reduce the effect of cladding mode upon coupling of optical fibers and is excellent in characteristic stability can be manufactured at a low cost.