Continuous motion of interference patterns using the angular Doppler effect

摘要

We demonstrate the use of the angular Doppler effect to obtain continuous motion of interference patterns. A small frequency shift between two beams can create such a moving pattern. By rotating a half wave plate in one arm of an interferometer, frequency shifts in the optical domain from less than 1 Hertz to kHz are achieved. We apply moving interference patterns in an optical tweezers set-up to enable controlled and continuous motion of optically trapped particles and structures.