We present a tunable mode filter for spatially multiplexed laser beams carrying orbital angular momentum (OAM). The filter comprises an optical geometric transformation-based OAM mode sorter and a spatial light modulator (SLM). The programmable SLM can selectively control the passing/blocking of each input OAM beam. We experimentally demonstrate tunable filtering of one or multiple OAM modes from four multiplexed input OAM modes with vortex charge of , , , and . The measured output power suppression ratio of the propagated modes to the blocked modes exceeds 14.5 dB.
© 2014 Optical Society of AmericaFull Article | PDF Article
Gregorius C. G. Berkhout, Martin P. J. Lavery, Miles J. Padgett, and Marco W. Beijersbergen
Opt. Lett. 36(10) 1863-1865 (2011)
Matthew E. Anderson, Heath Bigman, Luís E. E. de Araujo, and Jan L. Chaloupka
J. Opt. Soc. Am. B 29(8) 1968-1976 (2012)
Malcolm N. O’Sullivan, Mohammad Mirhosseini, Mehul Malik, and Robert W. Boyd
Opt. Express 20(22) 24444-24449 (2012)