Super-resolution variable fiber optic attenuator instrument using digital micromirror device (DMD™)

Demonstrated is a super resolution, low loss, 100% repeatable and fast response digital variable fiber-optic attenuator instrument using a digital micromirror device. The attenuator design exploits beam expansion optics and a retroreflective architecture to achieve super-resolution with digital repeatability. The proof-of-concept attenuator at 1550nm demonstrates a 41.5dB optical attenuation range, optical insertion loss of 3.8dB, a 1ms maximum attenuation reset time, an optical polarization dependant loss of less than 0.07dB, and an optical resolution range of 2.9–0.0517mdB. The demonstrated attenuator is appropriate for fiber-optic test and instrumentation applications.