| 摘要 |
<p>PROBLEM TO BE SOLVED: To measure exact grasp and length discrimination of optical path delay of a sub line to a main line from one end side of an optical fiber line.SOLUTION: Delay of a sub line 19 to a main line 18 is measured by generating a random pulse optical signal with wavelengthλwhich is a function of time t, making the random pulse optical signal incident on the sub line 19 by an optical circulator 119, after that, transmitting the random pulse optical signal from an optical coupler 14 to the main line 18, reflecting the random pulse optical signal by a reflection filter 118, bifurcating the reflected optical signal by the optical coupler 14, making one incident on the sub line 19, converting wavelength from the wavelengthλto wavelengthλdifferent from the wavelength, multiplexing a reflected optical signal with the reflected optical signal with the wavelengthλpassing through the main line 18, demultiplexing the reflected optical signal into the respective random pulse optical signals with the wavelengthλand the wavelengthλ, and calculating a cross correlation function using the delay as a function for optical current to be obtained from the respective pieces of signal light.</p> |
