摘要
搭建了一套光纤相位噪声抑制系统。通过环外自拍频,得到噪声本底的秒级频率稳定度为6.8×10~(-18),2000s平均时间后达到2.3×10~(-19)。利用该系统可实现窄线宽激光频率在1.6km实际光纤链路中的传输,传输后环外自拍频信号的秒级频率稳定度可达1.2×10~(-17)。基于连接两个实验室的808m实际光纤链路,将此系统应用于1.5μm超稳激光的比对,通过拍频测量得到激光线宽为(0.54±0.15)Hz,秒级频率稳定度为1.2×10~(-15)。
A fiber phase noise suppression system is built.By out-of-loop self-beat frequency,the noise floor of 6.8×10~(-18) is obtained in the average time of 1s,and it falls down to 2.3×10~(-19) after the average time of 2000s.The laser frequency with narrow linewidth is transferred in a 1.6km fiber link when we use the proposed system,and the frequency stability of out-of-loop self-beat frequency signal is 1.2×10~(-17) in the average time of 1s.Based on the 808 mfiber link which connects the two laboratories,the laser linewidth of(0.54±0.15)Hz and the frequency stability of 1.2×10~(-15) in average time of 1s can be obtained in beat frequency measurement when we apply the proposed system to the comparison of 1.5μm ultra-stable laser systems.
引文
[1]Hinkley N,Sherman J A,Phillips N B,et al.An atomic clock with 10-18 instability[J].Science,2013,341(6151):1215-1218.
[2]Bloom B J,Nicholson T L,Williams J R,et al.An optical lattice clock with accuracy and stability at the 10-18 level[J].Nature,2014,506(7486):71-75.
[3]Huntemann N,Sanner C,Lipphardt B,et al.Single-ion atomic clock with 3×10-18 systematic uncertainty[J].Physical Review Letters,2016,116(6):063001.
[4]Nicholson T L,Campbell S L,Hutson R B,et al.Systematic evaluation of an atomic clock at 2×10-18 total uncertainty[J].Nature Communications,2015,6:6896.
[5]Jiang Y Y,Ludlow A D,Lemke N D,et al.Making optical atomic clocks more stable with 10-16 level laser stabilization[J].Nature Photonics,2011,5(3):158-161.
[6]Kessler T,Hagemann C,Grebing C,et al.A sub-40-mHz-linewidth laser based on a silicon single-crystal optical cavity[J].Nature Photonics,2012,6(10):687-692.
[7]Hfner S,Falke S,Grebing C,et al.8×10-17 fractional laser frequency instability with a long room-temperature cavity[J].Optics Letters,2015,40(9):2112-2115.
[8]Jiang Yanyi.Narrow linewidth lasers:Application to optical clocks[D].Shanghai:East China Normal University,2012.蒋燕义.超窄线宽激光及其在光钟中的应用[D].上海:华东师范大学,2012.
[9]Lin Baike,Cao Shiying,Zhao Yang,et al.A compact iodine-stabilized solid-state laser at 532nm[J].Chinese JLasers,2014,41(9):0902002.林百科,曹士英,赵阳,等.小型化碘稳频532nm固体激光器[J].中国激光,2014,41(9):0902002.
[10]Fan Xialei,Jin Shangzhong,Zhang Shu,et al.Active suppression of residual amplitude modulation in laser frequency stabilization by multi-frequency mixing[J].Chinese J Lasers,2016,43(4):0402001.范夏雷,金尚忠,张枢,等.多频率合成主动抑制激光稳频的剩余幅度调制[J].中国激光,2016,43(4):0402001.
[11]Foreman S M,Ludlow A D,de Miranda M H G,et al.Coherent optical phase transfer over a 32-km fiber with 1s instability at 10-17[J].Physical Review Letters,2007,99(15):153601.
[12]Droste S,Ozimek F,Udem T,et al.Optical-frequency transfer over a single-span 1840km fiber link[J].Physical Review Letters,2013,111(11):110801.
[13]Ma L S,Jungner P,Ye J,et al.Delivering the same optical frequency at two places:Accurate cancellation of phase noise introduced by an optical fiber or other time-varying path[J].Optics Letters,1994,19(21):1777-1779.
[14]Jiang H,Kéfélian F,Crane S,et al.Long-distance frequency transfer over an urban fiber link using optical phase stabilization[J].Journal of the Optical Society of America B,2008,25(12):2029-2035.
[15]Ma C Q,Wu L F,Jiang Y Y,et al.Optical coherence transfer over 50-km spooled fiber with frequency instability of2×10-17 at 1s[J].Chinese Physics B,2015,24(8):084209.
[16]Xu Yongcun.The influence of optical fiber phase noise on transmission of narrow-linewidth laser and the technique of phase noise cancellation[D].Shanghai:East China Normal University,2009:10-11.徐永存.光纤相位噪声对传输窄线宽激光的影响及抑制技术的研究[D].上海:华东师范大学,2009:10-11.
[17]Li Y,Lin Y G,Zhao Y,et al.Stable narrow linewidth 689nm diode laser for the second stage cooling and trapping of strontium atoms[J].Chinese Physics Letters,2010,27(7):074208.