Multichannel Smart Slit Assembly for Spectroscopy Based on Arrays of Variable Optical MEMS Attenuators

We present design, fabrication and experimental characterization of a multichannel Smart Slit Assembly for next generation spectrometers, based on an array of 40 variable optical attenuators employing MEMS shutters integrated with large core multimode rectangular waveguides. The MEMS actuated shutters are fabricated in a 211 µm thick device layer of a Silicon-On-Insulator wafer by Deep Reactive Ion Etching. We experimentally demonstrate high shutting efficiency of 99.97% at 532 nm and fast reconfiguration <500 µs with 74 V actuation voltage. We also experimentally demonstrate a significantly expanded operating wavelength range up to the SWIR region using conformal Platinum coating while keeping a shutting efficiency exceeding 99.9%.