Variable attenuation electro-optic device
AssigneeNorthern Telecom Limited
InventorsWilliam J. Sinclair, Josef Straus, Philip M. Garel-Jones
Life of this patent
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Abstract
A variable attenuation electro-optic device has a lens for collimating light from an input fiber and for focussing light into an output fiber. The optical path of light passing through the device passes through a dynamic scattering liquid crystal cell whose optical transmissivity can be varied by varying an AC electric field applied across it. Reflective and transmissive embodiments are described using one or two lenses of the Selfoc.RTM. type. The applied AC introduces a frequency component into the attenuation which is suppressed to particularly adapt the device for use as an attenuator or enhanced and modulated to particularly adapt the device for use as a modulator.
Claims8
An electro-optic device comprising a graded refractive index lens for collimating input light at a liquid crystal cell and for focussing output light from the cell, the cell having a film of liquid crystal material flanked by first and second conducting films for applying an electric field across the liquid crystal to alter its optical transmissivity, and a reflector on a side thereof remote from the lens for reflecting input light propagating through the cell back through the lens.
Dependencies are inferred from the claim text.