title: Manifestation of the rotational Doppler effect by use of an off-axis optical vortex beam.
abstract: We report what is to our knowledge the first all-optical detection of the frequency beats between Gaussian and Laguerre-Gaussian LG0(1) modes in their axial superposition, caused by the rotational Doppler effect. The relation between the observable off-axis optical vortex rotation and the rotational frequency shift of the Laguerre-Gaussian component is ascertained. The results can be used as a physical basis for recognition of Laguerre-Gaussian mode spectra along their orbital angular momenta.
authors.affiliation: Institute of Physics, National Academy of Sciences of Ukraine, Prospect Nauki 46, Kiev 03028, Ukraine.
authors.forename: I V
authors.initials: IV
authors.lastname: Basistiy
authors.forename: V V
authors.initials: VV
authors.lastname: Slyusar
authors.forename: M S
authors.initials: MS
authors.lastname: Soskin
authors.forename: M V
authors.initials: MV
authors.lastname: Vasnetsov
authors.forename: A Ya
authors.initials: AY
authors.lastname: Bekshaev