| 摘要 |
Controllable fiber optic attenuators and attenuation systems are disclosed for controllably extracting optical energy from a fiber optic, and therefore attenuating the optical signal being transmitted through the fiber optic. A portion of the fiber optic is etched or tapered, thereby providing a side surface through which optical energy can be extracted. The portion of the fiber is suspended between two support points, and a controllable material is formed over the surface for controllably extracting optical energy according to a changeable stimulus applied thereto, which affects the refractive index thereof. In one embodiment, the changeable stimulus is temperature, and a controllable heating/cooling source can be provided in the attenuator for control of the attenuation. The limited amount of thermal contact between the suspended portion of the fiber optic and the controllable material to surrounding structures offers a more predictable response, and improved response time. The controllable material, in one embodiment, may be a dispersion controlled (e.g., matched) polymer, offering uniform spectral characteristics of attenuation across a wavelength band of interest.
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