Optical MEMS filter for gas spectroscopy

An optical MEMS filter for infrared spectroscopy has been designed, fabricated, and tested. The filter is a deformable hologram which combines focusing and optical filtering into one element. By modulating sections of the hologram, transmission spectra adapted to the absorption lines of a gas can be generated, allowing accurate measurements of gas concentration. The device is fabricated by micromachining grooves in silicon on top of an electrostatic actuator.