Rotational Doppler shift upon reflection from a right angle prism
Olivier Émile, Janine Émile, Christian Brousseau
Abstract
This Letter reports the observation of a rotational Doppler shift on reflected beams carrying Orbital Angular Momentum (OAM). More precisely, we study the beat frequency of two optical beams carrying OAM with opposite signs, reflected on a right angle prism. We show that the interference of the two beams leads to a daisy-like pattern that rotates at twice the rotating frequency of the prism. The rotational Doppler frequency shift is equal to the OAM topological charge change times the rotational frequency. Possible applications in the positioning and detection of rotation of objects are then discussed.
Topics & Concepts
Doppler effectOpticsAngular momentumPhysicsPrismRotation (mathematics)Interference (communication)Beat (acoustics)Reflection (computer programming)TelecommunicationsComputer scienceGeometryClassical mechanicsMathematicsChannel (broadcasting)AstronomyProgramming languageOrbital Angular Momentum in OpticsPhotonic and Optical DevicesForce Microscopy Techniques and Applications