High-speed non-mechanical beam steering using a swelling liquid crystal gel film with polymer concentration gradient

Abstract

We report refraction-type non-mechanical beam steering using a 100 μm thick swelling liquid crystal (LC) gel film with a polymer concentration gradient, in which an electrically-induced, large refractive index gradient along the uniaxial direction causes the deviation of a laser beam incident perpendicularly to the LC gel film. The swelling LC gel film is fabricated by polymerizing a LC-monomer/LC mixture while cooling it at a low temperature of −20 °C, and exhibits a short decay response time on the order of tens of microseconds. Thus, our device demonstrates non-mechanical beam steering with scan rate greater than 1 kHz.