| 摘要 |
<P>PROBLEM TO BE SOLVED: To obtain an optical fiber microwave transmission device capable of compensating for fluctuations in an optical path length. <P>SOLUTION: An optical fiber microwave transmission device includes: an E/O converter 2 for outputting a modulated light modulated by a microwave; an optical demultiplexer 4 for demultiplexing an optical frequency comb-shape signal into two optical frequency comb-shape signals S1, S2; an optical multiplexer 5 for multiplexing the modulated light and the comb-shape signal S1; a variable delay line 7 for varying an optical path length according to a control signal C1; an optical frequency shifter 13 for shifting the frequency of the comb-shape signal S1 reflected by a partial reflector 9; WDMs 14, 15 for demultiplexing light having wavelengths of λm and λ<SB POS="POST">n</SB>from the comb-shape signals S1, S2 according to a control signal C2; a phase comparator 20 for multiplexing the light of λm and λ<SB POS="POST">n</SB>and obtaining a phase difference of the microwave converted photoelectrically; and a control device 21 for controlling the variable delay line 7 and the WDMs 14, 15 to obtain the smaller optical path length difference between the two optical paths based on the phase difference, and a larger frequency difference when the optical path length difference becomes smaller than a predetermined threshold value. <P>COPYRIGHT: (C)2012,JPO&INPIT |
