Controlled switching of orbital angular momentum in an optical parametric oscillator

Abstract

Controlled switching of orbital angular momentum (OAM) of light at practical powers over arbitrary wavelength regions can have important implications for future quantum and classical systems. Here we report on a single source of OAM beams based on an optical parametric oscillator (OPO) that can provide all such capabilities. We demonstrate active transfer of OAM modes of any order, |lp|, of pump to the signal and idler in an OPO, to produce |lp|+1 different OAM states by controlling the relative cavity losses of the resonated beams. As a proof-of-principle, we show that when pumping with the OAM states |lp|=1 and |lp|=2 for different relative losses of signal and idler, the OPO has two (|1,0⟩ and |0,1⟩) and three (|2,0⟩, |1,1⟩, and |0,2⟩) output states, respectively. Our findings show that using a suitable loss modulator, one can achieve rapid switching of the OAM mode in OPO output beams in time.