Excess phase noise characterization in multifrequency remote clock distribution based on femtosecond frequency combs
© 2015 by the authors; licensee MDPI, Basel, Switzerland. Remote distribution of optical frequency references, based on multifrequency sources such as femtosecond frequency combs, holds many advantages over its single-frequency counterpart. However, characterizing the excess noise caused by the transmission links or external perturbations in a multifrequency scheme posts new challenges. We have experimentally demonstrated direct measurement of excess phase noise spectrum in both free-space and fiber-optic transfer of a frequency comb using a multiheterodyne technique. In fiber-optic distribution, we focused on the excess phase noise under a single-tone acoustic perturbation. Increased overall noise power and a change of phase noise spectrum have been observed. In free-space distribution, a fractional instability of 3 × 10-14 at 1 s was observed for a 60 m outdoor atmospheric transmission, and large phase modulation due to air fluctuations causes a sizable line broadening.
Applied Sciences (Switzerland)
Hu, C., Gollapalli, R., Yang, L., & Duan, L. (2015). Excess phase noise characterization in multifrequency remote clock distribution based on femtosecond frequency combs. Applied Sciences (Switzerland). Retrieved from https://ir.una.edu/engi_facpub/6