By using a self-reference transfer oscillator method,two individual 1560 nm lasers with about 1.2 GHz frequency difference were phase locked to a 729 nm ultra-stable laser at two preset ratios.By measuring the beat fr...By using a self-reference transfer oscillator method,two individual 1560 nm lasers with about 1.2 GHz frequency difference were phase locked to a 729 nm ultra-stable laser at two preset ratios.By measuring the beat frequency of the two 1560 nm lasers,fractional instabilities of 2×10^(−17) at 1 s and 2×10^(−20) at 10,000 s averaging time were obtained,and the relative offset compared with the theoretical value was 4.2×10^(−21)±4.5×10^(−20).The frequency ratio of them was evaluated to a level of 1.3×10^(−20) in one day’s data acquisition.This work was a preparation for remote comparison of optical clocks through optical fiber links.The technique can also be used to synthesize ultra-stable lasers at other wavelengths.展开更多
基金This work was supported by the National Key R&D Program of China(Nos.2017YFA0304403 and 2020YFA0309801)the Strategic Priority Research Program of the Chinese Academy of Sciences(Nos.XDB21010300 and XDB21030100)the National Natural Science Foundation of China(Nos.91636110 and U1738141).
文摘By using a self-reference transfer oscillator method,two individual 1560 nm lasers with about 1.2 GHz frequency difference were phase locked to a 729 nm ultra-stable laser at two preset ratios.By measuring the beat frequency of the two 1560 nm lasers,fractional instabilities of 2×10^(−17) at 1 s and 2×10^(−20) at 10,000 s averaging time were obtained,and the relative offset compared with the theoretical value was 4.2×10^(−21)±4.5×10^(−20).The frequency ratio of them was evaluated to a level of 1.3×10^(−20) in one day’s data acquisition.This work was a preparation for remote comparison of optical clocks through optical fiber links.The technique can also be used to synthesize ultra-stable lasers at other wavelengths.
