Patent ID: 7373024
Filing Date: 2008-05-13
Classification: G02F

Abstract:
1. An apparatus selectively operable as an on-fiber microwave modulator and high speed switch for modulating and switching off an optical signal transmitted in an optical fiber, comprising: an optical fiber having a core surrounded by a cladding material, and having a region wherein the passive cladding material has been removed to form an exposed core surface; a modified fiber including a layer of a coated material surrounding the fiber core comprising an electrooptic active material coated on said exposed surface of the fiber core; the electrooptic material surrounding the fiber core has an adjustable index of refraction which is changed by an external electromagnetic field applied to the modified section; a microwave cavity positioned around the modified fiber where said optical fiber is passing through the cavity in the direction of said the cavity main axis to provide the modulating microwave electromagnetic field applied to the electrooptic material; a light source for providing an optical signal carrier for communication signals transmission into said optical fiber and providing a reference signal; means for applying an external microwave modulating communication signal to the electrooptic material through said microwave cavity to change the optical properties of the modified region to modulate the optical signal in said optical fiber core; first detector means positioned on said optical fiber downstream from said light source and said region of modified fiber for detecting optical signals in said optical fiber and transfer optical signals to electrical signals; and signal processing means for amplifying an output signal of said detector while also providing demodulation of the electric signal to separate the transmitted communication signal, wherein said reference signal from said light source is used to provide a noise free signal output, said signal output is the electronic communication signal.