In this paper,we present a remote time-base-free technique for a coherent optical frequency transfer system via fiber.At the remote site,the thermal noise of the optical components is corrected along with the link pha...In this paper,we present a remote time-base-free technique for a coherent optical frequency transfer system via fiber.At the remote site,the thermal noise of the optical components is corrected along with the link phase noise caused by environmental effects.In this system,a 1×2 acousto-optic modulator(AOM)is applied at the remote site,with the first light being used to eliminate the noise of the remote time base and interface with remote users while the zeroth light is used to establish an active noise canceling loop.With this technique,a 10 MHz commercial oscillator,used as a time base at the remote site,does not contribute to the noise of the transferred signal.An experimental system is constructed using a 150 km fiber spool to validate the proposed technique.After compensation,the overlapping Allan deviation of the transfer link is 7.42×10^(-15)at 1 s integration time and scales down to 1.07×10^(-18)at 10,000 s integration time.The uncertainty of the transmitted optical frequency is on the order of a few 10-19.This significantly reduces the time-base requirements and costs for multi-user applications without compromising transfer accuracy.Meanwhile,these results show great potential for transferring ultra-stable optical frequency signals to remote sites,especially for point-to-multi-users.展开更多
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB21000000)the Open Project Fund of State Key Laboratory of Transient Optics and Photonics,Chinese Academy of Sciences(No.SKLST202011)+1 种基金the National Natural Science Foundation of China(Nos.12103059,12103059,12303076,and 12303077)the Planned Project of Xi’an Bureau of Science and Technology,China(No.E019XK104).
文摘In this paper,we present a remote time-base-free technique for a coherent optical frequency transfer system via fiber.At the remote site,the thermal noise of the optical components is corrected along with the link phase noise caused by environmental effects.In this system,a 1×2 acousto-optic modulator(AOM)is applied at the remote site,with the first light being used to eliminate the noise of the remote time base and interface with remote users while the zeroth light is used to establish an active noise canceling loop.With this technique,a 10 MHz commercial oscillator,used as a time base at the remote site,does not contribute to the noise of the transferred signal.An experimental system is constructed using a 150 km fiber spool to validate the proposed technique.After compensation,the overlapping Allan deviation of the transfer link is 7.42×10^(-15)at 1 s integration time and scales down to 1.07×10^(-18)at 10,000 s integration time.The uncertainty of the transmitted optical frequency is on the order of a few 10-19.This significantly reduces the time-base requirements and costs for multi-user applications without compromising transfer accuracy.Meanwhile,these results show great potential for transferring ultra-stable optical frequency signals to remote sites,especially for point-to-multi-users.
