Tailoring of arbitrary optical vector beams

TLDR

Vector beams share intensity profiles with scalar Laguerre–Gaussian or Hermite–Gaussian modes but possess spatially varying polarization, and radially or azimuthally polarized doughnut modes offer superior focusing and promise applications in optical trapping, spectroscopy, and super‑resolution microscopy. The authors aim to develop a robust interferometric method to generate arbitrary vector beam modes. They achieve this by diffracting a Gaussian laser beam with a high‑resolution reflective nematic liquid‑crystal spatial light modulator. The system allows video‑rate switching between vector beam modes and produces high‑quality Hermite–Gaussian and Laguerre–Gaussian vector beams, vectorial anti‑vortices, and mixed‑mode beams with non‑symmetric polarization, while radially or azimuthally polarized doughnut modes exhibit superior focusing and promise applications in optical trapping, spectroscopy, and super‑resolution microscopy.

Abstract

We present a robust interferometric method to generate arbitrary vector beam modes by diffracting a Gaussian laser beam from a spatial light modulator consisting of a high-resolution reflective nematic liquid crystal display. Vector beams may have the same intensity cross-section as the more common scalar Laguerre–Gaussian (LG) or Hermite–Gaussian (HG) beams, but with a spatially modulated polarization distribution. Special cases are the radially or azimuthally polarized 'doughnut' modes, which have superior focusing properties and promise novel applications in many fields, such as optical trapping, spectroscopy and super-resolution microscopy. Our system allows video rate switching between vector beam modes. We demonstrate the generation of high quality Hermite–Gaussian and Laguerre–Gaussian vector beam modes of different order, of vectorial anti-vortices, and of mode mixtures with interesting non-symmetric polarization distributions.