Compensation of noise floor distortion in long-range simplified optical correlation-domain reflectometry without the use of electrical spectrum analyzer

Abstract

In simplified optical correlation-domain reflectometry (OCDR) without the use of an electrical spectrum analyzer (ESA), the noise floor of the reflectivity distribution is distorted in long-range measurement, which sometimes causes significant errors in the distributed reflectivity measurement. Herein, we experimentally analyze the distorted noise floor by high-speed ESA-free OCDR and clarify the origin of the noise floor. Then we show that this noise floor can be compensated by appropriate filtering. Consequently, distributed reflectivity measurement over a 1.1 km long sensing fiber is properly performed at a repetition rate of 100 Hz.