US Patent 7440156 Integrated fiber optical attenuator with monotonic attenuation

Designs of optical devices for attenuating a light signal are disclosed. According to embodiment, an attenuator includes a screw and a light blocker, wherein the light blocker has only translational movements when the screw is screwed in or out. To facilitate the light signal in and out, a first collimator to receive a light beam, and a second collimator to output the light beam, wherein the light beam is attenuated by the light blocker when the light is transmitted from the first collimator to the second collimator.