An optical device for rerouting and modifying an optical signal that uses a
double pass through a liquid crystal modulator is disclosed. The optical
device includes a first polarizer for providing polarized light, a liquid
crystal modulator for selectively modifying the polarized light, a second
polarizer for analyzing the light passed through the liquid crystal
modulator, and a reflector for reflecting the analyzed light back through
the second polarizer, the liquid crystal modulator, and the first
polarizer. This arrangement provides a double pass through the liquid
crystal modulator, thus significantly improving the attainable extinction
ratio.