Spectroscopy of fractional orbital angular momentum states

Abstract

We present an approach for measuring the orbital angular momentum (OAM) of light tailored towards applications in spectroscopy and non-integer OAM values. It is based on the OAM sorting method (Berkhout et al., Phys. Rev. Lett. 105, 153601 (2010)). We demonstrate that mixed OAM states and fractional OAM states can be identified using moments of the sorted output intensity distribution and OAM states with integer and non-integer topological charge can be clearly distinguished. Furthermore the difference between intrinsic OAM and total OAM for fractional OAM states is highlighted and the importance of the orientation of the fractional OAM beam is shown. All experimental results show good agreement with simulations. Finally we discuss possible applications of this method for spectroscopy of semiconductor systems such as exciton-polaritons in microcavities.

arXiv comment17 pages, 5 figures

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• Efficient separation of the orbital angular momentum eigenstates of light
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Cited by in corpus (3)

• Realization of all-optical vortex switching in exciton-polariton condensates
• On vortex strength and beam propagation factor of fractional vortex beams
• Formation dynamics of exciton polariton vortices created by non-resonant annular pumping