Patent ID: 7149391

Claim:
Apparatus selectively operable as a two dimensional array of couplers or switches wherein each element of the array is an on-fiber coupler, said elements are arranged in a series and parallel connections adapted to couple the input signal of any element to the output communication line of any other element in the array, wherein each element is a tunable coupler comprising: a first optical fiber and a second optical fiber, each of said fibers having a core and a cladding material surrounding the core, and each of said fibers having a region wherein the cladding has been removed to form a region of uncladding, said regions of uncladding being positioned parallel and close to each other while preventing mechanical movement of said fibers in relation to each other; each fiber core is coated, in said region of uncladding, all over the 360° of the cylindrical surface, with a thin layer of metallic material to construct the inner (or first) electrode on each fiber core; a layer of an electrooptic material is coated on the tope of each inner (first) electrode and around the two fibers as well as filling the gap between the fibers; on the top of the electrooptic material, a layer of metallic material is coated allover the surface (360°) to construct the outer (or second) electrode, the inner and outer electrodes are used to apply electromagnetic fields to the electrooptic material in a symmetric radial directions with respect to the two fiber cores; the field lines are oriented in a symmetric configuration with respect to the fibers circular cross section in order to provide a polarization independent coupling; means for applying an external electric signal to said modified fibers to change said optical properties of the modified region to transfer partially or totally the optical signal from the first optical fiber to the second optical fiber; a light source means focused to provide an optical communication signal into said first optical fiber and a reference signal; detector means positioned on said each optical fiber downstream from said light source and said region of modified fiber for detecting optical signals in said optical fiber and said reference signal and transfer optical signals to electrical signals; and signal processing means coupled with said detectors means to amplify and process any output signals of said detectors, wherein said reference signal from light source is used to provide a noise free coupler outputs.