Optically Powered Pressure Sensor with Optical Fiber Link

摘要

An optically powered sensor for measuring pressure which is linked by optical fiber is developed in new scheme. Its pulse position modulation (PPM) optical signal and optical supply power for electronics in probe are transmitted via a single optical fiber . The optical power is carried by a 1 300 nm laser diode (LD) and the sensing data are carried by a 850 nm LED. The remote probe uses all CMOS chips and particular modulations (PPM and PWM). Its electrical consumption including signal manipulation and LED driven current from optically converted is less than 100 μW. The laser diode supplies 5 mW optical power into the fiber. A photodetector converts sufficiently this power into electrical power to drive the whole probe operation. The optically powered distance gets up to 500 m. The novel sensor combines optical fiber and electronics technology into a system. Because of using the principle of ratio measurement between measured and reference signals, as well as light feedback, the system is available with high reliable, outstanding accuracy and repeatability.