Retro-reflection type MOEMS VOA

Novel microoptoelectromechanical systems (MOEMS) variable optical attenuators (VOAs) using retro-reflection attenuation scheme with initially open and closed states are proposed and characterized in this letter. This VOA device is comprised of two movable reflective micromirrors that are allocated in the front of input and output fibers and then assembled in a planar coaxial layout. The measured characteristics exhibit dynamic range of 50 dB, insertion loss of less than 0.9 dB, backreflection loss of less than -50 dB, and wavelength-dependent loss of less than 0.57 dB at 30-dB attenuation, respectively. The MOEMS VOAs that attenuate light intensity using retro-reflection in free space is good for broad-band applications.