MEMS tilt-mirror spatial light modulator for a dynamic spectral equalizer

This paper presents a linear array of tilting mirrors used to attenuate the various wavelengths in a DWDM optical signal. Attenuation of 21 dB at snap-down was achieved by the tilting mirrors, substituting for a liquid crystal spatial light modulator (SLM) in a commercial dynamic spectral equalizer (DSE). Linear fill factor of 92% was achieved, allowing closely spaced wavelength channels to be individually attenuated. A two layer polysilicon process with a thick epi-poly mirror was used to fabricate the SLM. Initial mirrors had a radius of curvature of 25 cm. A novel accelerated HF-H/sub 2/SO/sub 4/ etch allowed 100 /spl mu/m wide mirrors to be undercut in 12 min with no etch release holes.