| 摘要 |
Provided is an electric field measuring device which allows very stable transmission and miniaturization of an electric field sensor head. An electric field measuring device for measuring the electric field intensity of an electromagnetic wave generated by a device to be measured (8) that is set in an area for detecting an electromagnetic wave, such as an anechoic darkroom (10), wherein an antenna (1) and an optical intensity modulator (head unit (2)) comprising a Mach-Zehnder type optical waveguide are provided in the area, and an output signal of the antenna is applied to a modulation electrode of the optical intensity modulator. Outside of the area, a body unit (6) is provided with a light source unit, a light receiving unit, and a DC bias control unit for controlling the DC bias voltage supplied to the optical intensity modulator according to the optical intensity of the light output from the optical intensity modulator. An optical wave is introduced from the light source unit into the optical intensity modulator via an optical fiber (4), an optical wave is led from the optical intensity modulator to the light receiving unit via the optical fiber (4), and the DC bias voltage is supplied from the DC bias control unit to the optical intensity modulator through an electrical supply line (4). |
