Open AccessMeasuring the complex orbital angular momentum spectrum of light with a mode-matching method
Author(s) -
Peng Zhao,
Shikang Li,
Xue Feng,
Kaiyu Cui,
Fang Liu,
Wei Zhang
Publication year - 2017
Publication title -
optics letters/optics index
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.524
H-Index - 272
eISSN - 1071-2763
pISSN - 0146-9592
DOI - 10.1364/ol.42.001080
Subject(s) - optics , angular momentum , physics , orbital angular momentum of light , mode (computer interface) , angular momentum of light , phase matching , total angular momentum quantum number , angular momentum coupling , classical mechanics , laser , computer science , operating system
The relative phase shift among different components in the superposition of orbital angular momentum (OAM) states contains significant information. However, with existing methods of measuring the OAM spectrum, the phase term of the spectrum coefficient is hard to obtain. In this Letter, a mode-matching method is proposed to identify the complex OAM spectrum with a Mach-Zehnder interferometer and a charge-coupled device camera. It has the potential to extend the applications of OAM in scenarios sensitive to the phase factor, for instance, in imaging and quantum manipulation. The method is experimentally demonstrated with the superposition of two or three OAM states, while the maximum deviation of the energy ratio and the relative phase shift is 8.4% and 5.5% of 2π, respectively.