Electric field intensity detecting device having a condenser-type antenna and a light modulator

An apparatus for measuring an electric field intensity comprising:

• light generating means for generating coherent measuring light;
• a sensor disposed in the electric field for modulating a measuring light according to the intensity of the electric field and for outputting said modulated light;
• an up-link optical fiber connecting between said light generating means and said sensor for guiding said measuring light into said sensor;
• a down-link optical fiber for guiding said modulated light outside said sensor;
• and
• intensity processing means disposed outside said sensor for processing said intensity of the electric field based on the degree of modulation of said measuring light inputted via said down-link optical fiber;
• wherein
• said sensor comprises a condenser-type antenna for detecting the electric field and outputting a voltage according to the intensity of the detected electric field, a waveguide-type optical integrated circuit in which a waveguide for propagating the inputted measuring light is formed, a light modulator, through which said waveguide extends, formed in said optical integrated circuit, and a light modulator electrode for applying the output voltage of said condenser-type antenna to said waveguide of said light modulator, whereby the measuring light is modulated according to the intensity of the electric field while the measuring light is propagated through said waveguide of said light modulator.