| 摘要 |
<P>PROBLEM TO BE SOLVED: To measure the modulation factor of self phase modulation in an optical fiber transmission path. <P>SOLUTION: An output laser beam having λp of wavelength from a wavelength variable light source 14 is intensity-modulated by an intensity modulator 18, and phase-modulated by a phase modulator 22. A dummy light source 24 outputs dummy light having λ1-λn of wavelength range. A photocoupler 26 multiplexes output light from the phase modulator 22 with the dummy light from the dummy light source 24, and a multiplexed light is input into an optical BPF 32 via a photocoupler 28, a gain eqaulizer 30 and the optical fiber transmission path 10. An optical BPF 32 extracts a measuring light having the λp of wavelength from the input light, and an output therein is input into a BER measuring instrument 38 via a photoreceiver 36. A controller 12 measures the modulation factor of phase modulation in a phase modulator 22 by a light spectrum analyzer 30, after adjusting a phase and an amplitude of a drive signal for the phase modulator 22 to bring a BER into the minimum. The measuring wavelength λp is swept to measure a wavelength change in the optimum phase modulation factor. The measured phase modulation factor represents the SPM modulation factor of the optical fiber transmission path 10. <P>COPYRIGHT: (C)2004,JPO |
