A PDMS-on-Silicon Deformable Grating for Spectral Differentiation of Mixed Wavelength Signals

We present an innovative optical MEMS device containing a polymer micro-bridge with a tunable diffraction grating period. A periodicity tunability of 12% is measured, and high speed spectroscopic measurements with the use of only a single photodetector are demonstrated. The optical setup analyzes a continuous spectrum of wavelengths with a range up to 70 nm and at kHz speed. We demonstrate the spectral acquisition capabilities by differentiating the intensity from two lasers of wavelength 593 nm and 633 nm. This device may be suitable for integration with a microfluidics system for high speed, highly sensitive multiple wavelength detection in lab-on-a-chip biological assay settings.