Simple spatial phase modulator for focal modulation microscopy

Focal modulation microscopy (FMM) is an emerging microscopy technique for fluorescence imaging of thick biological tissue in vivo. A spatial phase modulator is a critical component whose characteristics have a significant impact on the performance of a FMM system. We have designed a simple spatial phase modulator based on a tilting glass plate that provides superb modulation stability. Image quality has been improved remarkably after integrating such a modulator into a FMM system. OCIS codes: 180.2520, 110.0113, 120.5060, 230.4110.