Measurement of the orbital angular momentum density of Bessel beams by projection into a Laguerre-Gaussian basis.

ABSTRACT

We present the measurement of the orbital angular momentum (OAM) density of Bessel beams and superpositions thereof by projection into a Laguerre-Gaussian basis. This projection is performed by an all-optical inner product measurement performed by correlation filters, from which the optical field can be retrieved in amplitude and phase. The derived OAM densities are compared to those obtained from previously stated azimuthal decomposition yielding consistent results.