Abstract

A wide variety of laser-tuning mechanisms exist based on analogue mechanical or thermal effects. It is important for a number of applications, including communications¹ and spectroscopy, to have precise, repeatable, and reliable wavelength control. We present here a digital wavelength tuning mechanism, which is inherently stable, precise, and repeatable. The novel filter is based on a pixellated2-D ferroelectric liquid crystal (FLC) spatial light modulator (SMA), whose fundamental spatial periodicity (pixel dimension) is accurately defined by a photo-lithographic process. The FLC at each pixel can be electro-optically controlled into one of two bistable states, which can be configured to give either 0 or π phase modulation of the light passing through.

© 1996 Optical Society of America