Generation of broadband ultraviolet orbital angular momentum for quantum optical coherence tomography

We investigate two different approaches for imprinting orbital angular momentum (OAM) on different spectral components of a broadband ultraviolet beam with wavelength 350-500 nm for application in quantum optical coherence tomography. Two different approaches using a spiral phase plate (SPP) are studied to achieve this goal. The first approach involves using only a SPP, calibrated for a particular wavelength, for broadband application. However, this approach leads to the presence of unmodulated components in the output beam. In the second approach, combination of SPP and grating is used to remove the unmodulated part and to filter out the imprinted OAM beam. ACKNOWLEDGEMENTS This work is supported by Villum Fonden (Villum Investigator project Table-Top Synchrotrons, No. 00037822) and Horizon Europe, the European Union’s Framework Programme for Research and Innovation, under Grant Agreement No. 101070062 (SEQUOIA). Views and opinions expressed are however those of the authors only and do not necessarily reflect those of the European Union. The European Union cannot be held responsible for them.