Input and output devices for optical fiber
AssigneeNippon Telegraph & Telephone Public Corporation
InventorsAkira Sugimura, Naoya Uchida, Tatsuya Kimura
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Abstract
Input and output devices for an optical fiber include an acoustic transducer for generating a planar acoustic wave tilted at an angle with respect to the axis of an optical fiber embraced by a quartz block. The gap between the optical fiber and the quartz block is filled with a liquid, such as water, to obtain acoustic impedance matching. A desired mode of propagating light can be extracted from the fiber or injected therein by reflection under Bragg's condition through a glass block and optical system without cutting or damaging the optical fiber.
Claims14
An acoustical output device for an optical, light conducting fiber, comprising:
- a quartz block having a semi-circular groove therein of a radius substantially equal to that of an elongated, circular optical fiber, said block having an inclined upper surface, an acoustic transducer secured to said upper surface, a glass block having a refractive index higher than that of the optical fiber and having a semi-circular groove therein of a radius substantially equal to that of the optical fiber, said glass block having an inclined bottom surface, the quartz block and the glass block being arranged to embrace the optical fiber within their respective grooves at a location where an output is desired, the inclined surfaces of the blocks being opposite each other with the narrower ends thereof together, an optically transparent sheet arranged between the groove of the glass block and the optical fiber, a liquid, such as water, provided between the optical fiber and the quartz block, such liquid having a low absorption loss for an acoustic wave and an acoustic impedance close to that of the quartz block to thereby cause a small reflection loss for an acoustic wave, the acoustic transducer being arranged to generate an acoustic wave having an inclined wave front with respect to the axis of the optical fiber along which light is propagated in guided modes to thereby cause light to be reflected by Bragg's condition to a radiation mode, and an optical output system aligned with a beam of output light emanated from the optical fiber, the optical output system being separably arranged from the glass block.
An acoustical input device for an optical, light conducting fiber, comprising:
- a quartz block having a semi-circular groove therein of a radius substantially equal to that of an elongated, circular optical fiber, said block having an inclined upper surface, an acoustic transducer secured to said upper surface, a glass block having a refractive index higher than that of the optical fiber and having a semi-circular groove therein of a radius substantially equal to that of the optical fiber, said glass block having an inclined bottom surface, the quartz block and the glass block being arranged to embrace the optical fiber within their respective grooves where an input is desired, the inclined surfaces of the blocks being opposite each other with the narrower ends thereof together, an optically transparent sheet arranged between the groove of the glass block and the optical fiber, a liquid, such as water, provided between the optical fiber and the quartz block, such liquid having a low absorption loss for an acoustic wave and an acoustic impedance close to that of the quartz block to thereby cause a small reflection loss for an acoustic wave, an optical input system aligned with a beam of input light and being arranged separably from the glass block, the acoustic transducer being arranged to generate an acoustic wave having an inclined wave front with respect to the axis of the optical fiber, such acoustic wave thereby causing a beam of input light to be injected by Bragg's condition into the optical fiber and propagated therein in a guided mode.
Dependencies are inferred from the claim text.