Holographic inscription of helical wavefronts in a liquid crystal polarization grating

摘要

A space-varying polarization hologram (PH) grating is fabricated in a nematic liquid crystal (LC) cell with azo-side-chain polymer alignment layers. The polarization-sensitive photoisomerization property of azo-side-chain polymer is utilized to inscribe the PH in a LC cell. Both transmission and reflection holographic configurations are adopted in fabrication. The transmission PH made by the circular orthogonal polarizations exhibits the polarization-controlled Laguerre-Gaussian beam generation, while the reflection PH made by the linear orthogonal polarizations generates a variety of Laguerre-Gaussian beam, though not polarization controlled.