Cost-effective demonstration of fiber-optic frequency transfer

In this paper, we demonstrate a cost-effective solution for fiber-optic frequency transfer. By employing the commercially available small form pluggable (SFP) transceivers and other components for telecom, the scheme is compatible with the existing telecom networks. An experiment testbed based on the common round trip frequency transfer is carried out to investigate the corresponding performance in detail. Compared with the conventional analog electro-optic interconversion scheme, the optical modulation and demodulation employing SFP transceiver has an inferior performance in terms of additive phase noise. However, the scheme enables a much larger operation range of receiving optical power for an optimal system performance, which indicates the certain capability of adapting to different fiber transmission links. On the basis of the established testbed, fiber-optic frequency transfer with a frequency of 1 GHz is demonstrated over a 50 km dispersion-compensated fiber link. Furthermore, the additive phase noise of -84dBc/Hz @1 Hz and -130dBc/Hz @10 kHz is achieved. Simultaneously, the Allan deviation (ADEV) of 9.6×10^-14/s and 8.4×10^-17/10⁴s is reached, respectively. The scheme can provide a relatively feasible solution to implement fiber-optic frequency transfer over the existing telecom network infrastructure.