Variable Attenuator Suits Fiber Optics

As an opto-mechanical device that controls light levels, the FVA-UV Fiber Optic Variable Attenuator couples via optical filters to spectrometers, light sources, and other sampling optics to uniformly attenuate light at all wavelengths. The attenuator consists of an aluminum block with threaded ports that hold two fiber-coupled collimating lenses. The attenuator is placed in line between light sources. A wheel with an aperture that varies in width along the circumference is fixtured between the collimating lenses. Rotating the wheel varies the fraction of light transmitted through the fixture. A thumbscrew locks the wheel in place. This device works at all wavelengths from UV-VIS through Shortwave NIR (200 to 1100 nm).