A Sagnac-like interferometer for the generation of vector beams

In this paper, we propose a Sagnac-like scheme, to transform Laguerre-Gaussian (LG) beams into vector beams. The experimental apparatus of our scheme consists of a polarized beam splitter, two reflectors, and a quarter-wave plate (QWP). Firstly, holograms of spiral phase plates were encoded on a liquid crystal spatial light modulator to generate different LG beams. Then, the generated LG beams were transformed into radially polarized vector beams. Azimuthally polarized vector beams were also obtained through placing a half-wave plate group behind the QWP. The intensity distribution of the generated vector beams is similar to the incident LG beams. A rotating polarizer is used to analyze the polarization distribution of the generated vector beams, and the results of which are highly consistent with the theoretical analysis.