Compressive sensing spectrometry based on liquid crystal devices

We present a new type of compressive spectroscopy technique employing a liquid crystal (LC) phase retarder. A tunable LCcellisusedinamanner compliant with the compressive sensing (CS) frameworktosignificantly reduce the spectral scanning effort. The presented optical spectrometer consists of a single LC phase retarder combined with a single photo detector, where the LC phase retarder is used to modulate the input spectrum and the photodiode is used to measure the transmitted spectral signal. Sequences of measurements are taken, where each measurement is done with a different state of the retarder. Then, the set of photodiode measurements is used as input data to a CS solver algorithm. Wedemonstrate numerally compressive spectral sensing with approximately ten times fewer measurements than with an equivalent conventional spectrometer.