OPTICAL ELECTRIC FIELD SENSOR

• Main Author: MIYAGAWA TOSHIYA
• Format: Patent
• Language: English
• Published: 30.07.1999
• Edition: 6
• Subjects: BASIC ELECTRIC ELEMENTS; DEVICES OR ARRANGEMENTS, THE OPTICAL OPERATION OF WHICH ISMODIFIED BY CHANGING THE OPTICAL PROPERTIES OF THE MEDIUM OF THEDEVICES OR ARRANGEMENTS FOR THE CONTROL OF THE INTENSITY,COLOUR, PHASE, POLARISATION OR DIRECTION OF LIGHT, e.g.SWITCHING, GATING, MODULATING OR DEMODULATING; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; FREQUENCY-CHANGING; MEASURING; MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES; NON-LINEAR OPTICS; OPTICAL ANALOGUE/DIGITAL CONVERTERS; OPTICAL LOGIC ELEMENTS; OPTICS; PHYSICS; SEMICONDUCTOR DEVICES; TECHNIQUES OR PROCEDURES FOR THE OPERATION THEREOF; TESTING

PROBLEM TO BE SOLVED: To provide an optical electric field sensor which enables its reliability increase and high-sensitivity electric field measurement as well. SOLUTION: A sensor head is fitted with a directional coupling type 3 dB coupler 22, and a photodetector 4 is composed of two photoelectric converters 5 and an arithmetic circuit 6. Two output lights of a directional coupling type 3 dB coupler 22 strike the two photoelectric converters 5, respectively. The output signal lights of the photoelectric converters 5 are insulted to the arithmetic circuit 6, and one output signal light of the photoelectric converters 5 by an output signal light of a smaller one out of the optical biases of the two output signal lights of the directional coupling type 3 dB coupler 22 is outputted selectively. Along with it, the intensity of emitted light of a light source 3 is controlled so that the intensity of the said optical bias may be constant.