Fractional topological-charge measurement of optical vortex beam using single-path interferometer

Optical vortex beam carrying fractional topological charges (TC) has become an emerging field of interest due to its unique intensity distribution and fractional phase front in transverse plane. Therefore, the accurate measurement of fractional TC is an importance issue. This study demonstrates a method of measuring the TC of fractional vortex beams using petal-shaped fringes obtained using a single-path interferometer. The method is easy to implement and offers efficient measurement of fractional TC.