Patent ID: 7209613

Claim:
An electromagnetic field sensing apparatus, comprising: a light source for generating a light beam; an optical modulator for changing a phase of the light beam propagating therethrough in response to an electric field; a miniature antenna for transforming a sensed electromagnetic field into an electric field and then applying to the optical modulator, the miniature antenna including: a first line; a first optical switch positioned at one end of the first line; a second optical switch positioned at the other end of the first line; a second line connected to the first optical switch; and a third line connected to the second optical switch; wherein the first optical switch and the second optical switch are turned on for sensing a magnetic field and turned off for sensing an electric field; a first optical fiber for transmitting the light beam to the optical modulator; a second optical fiber connected to the optical modulator; and an optical detector for transforming the light beam transmitted from the second optical fiber into an electrical signal.