OPTICAL FIBER MEASURING APPARATUS

摘要

PROBLEM TO BE SOLVED: To accurately obtain a change in time of the intensity of return light in an optical fiber. SOLUTION: The optical fiber measuring apparatus comprises: an acoustic optical element 22 for switching continuous light to zero-order light and high- order light according to the signal level of a pseudo random pulse signal for outputting; a multiplexer 24 for multiplying the zero-order light and high-order light outputted from the acoustic optical element for applying to the optical fiber as measurement light; a detector 27 for multiplying return light from the optical fiber and continuous light from the light source for executing optical heterodyne detection; a signal extraction section 30 for extracting a signal that changes with time for indicating a change in time of the intensity of return light from the detection signal outputted from the detector; a correlator 34 for calculating the correlation between the signal that changes with time and the pseudo random pulse signal for outputting as a correlation signal; and a characteristic calculation section 36 for calculating the characteristics of the optical fiber from the correlation signal. COPYRIGHT: (C)2004,JPO