Patent ID: 6859573

Claim:
An optical device comprising: a first optical fibre for providing an input beam of light; first polarizing means for producing light having a predetermined polarization state from the input beam of light; a liquid crystal modulator positioned to receive the light having a predetermined polarization state and for selectively altering its polarization; second polarizing means positioned to receive the light transmitted from the liquid crystal modulator, said second polarization means designed for passing light having one of the predetermined polarization and a polarization perpendicular to the predetermined polarization and for blocking or diverting the other; a reflective surface positioned to receive the light passed through the second polarizing means and reflect it for a second pass through the liquid crystal modulator; and a controller coupled to the liquid crystal modulator to direct the selective altering of polarization in dependence upon a desired attenuation setting for light exiting the optical device through one of the first optical fibre and a second optical fibre.