| 摘要 |
PROBLEM TO BE SOLVED: To obtain a large frequency shift quantity with high efficiency and to accurately shift a frequency to a position of an integral multiple of a specified frequency grid over a wide range. SOLUTION: After side bands (SB) are generated by modulating the phase of input light by an EOM 11 with a modulation frequency f<SB>m</SB>and a modulation indexΔθ<SB>m1</SB>and relative phases of the respective SBs are adjusted by a relative phase adjuster 13, the EOM 14 performs phase modulation with the modulation frequency f<SB>m</SB>and modulation indexΔθ<SB>m1</SB>to concentrate power on a specific SB nearby a degreeΔθ<SB>m2</SB>. Consequently, the frequency is shifted. After a relative phase adjuster 16 further performs relative phase adjustment having the opposite relation from the former relative phase adjustment, an EOM 17 performs phase modulation to cancel the phase modulation by the EOM 11 and then while the power is further concentrated on the specific SB, other SBs are suppressed. The shift quantity can be made greatly large since the frequency shift quantity depends upon the product of f<SB>m</SB>andΔθ<SB>m2</SB>, and accurate variable shifting can be performed by controlling theΔθ<SB>m2</SB>. COPYRIGHT: (C)2007,JPO&INPIT |
