Patent ID: 6946827

Claim:
An electric field sensing system for measuring electric field comprising: a light source for generating a primary light wave; first and second photodetectors for providing first and second photodetector electrical output signals, respectively, in response to any light impinging thereon, respectively; an optical electric field sensing head having, at least a first optical sensing element that exhibits an electro-optic effect where the transit time of light waves passing therethrough of different polarizations are affected differently in response to an electric field thereat; a first optical circuit responsive to said primary light wave for deriving first and second light wave components therefrom, and coupling said first and second light wave components to said optical sensing element, where said first and second light wave components have different polarizations and have a phase separation, φ o , and a second optical circuit for deriving third and fourth light waves of different polarization from a light wave exiting from said first optical sensing element, and directing said third and fourth light waves to impinge upon said first and second photodetectors, respectively; and a signal processor for deriving a processor output signal, E, representative of the electric field intended to be measured as a sensing system specific, X, characterized function, G x , mathematically described by: E=G x {a, b, E π , φ o , K, α} where, a and b represent resultant signal processor input signals derived from the first and second photodetector electrical output signals, respectively; E π is a sensing system specific parameter being substantially the average electric field required to create a π radian phase shift between optical polarization components traveling from the input to the output of said first optical sensing element in response to an electric field thereat, φ o is the equivalent intrinsic phase shift between the first and second light wave components, α is a number between 0 and 1 that characterizes the goodness of the specific electric field sensing system, X, and K is equal to the ratio K A /K B , where K A and K B are characteristic loss factors of the specific electric field sensing system, X, associated with said first and second processor input signals, respectively.