Fig. 1. Schematic of fiber-optic based time and frequency transfer system

Fig. 2. Diagram of optical frequency transfer system based on passive optical phase noise cancellation

Fig. 3. Performance comparison of two noise cancellation schemes

Fig. 4. Effective and group refractivity vs silicon waveguide dimensions. (a) Structure of conventional waveguide; (b) structure of polarization-insensitive waveguide; (c) n_eff vs w for conventional waveguide; (d) n_eff vs w for polarization-insensitive waveguide; (e) n_g vs w for polarization-insensitive waveguide

Fig. 5. Silicon-based transceiver chip and its transmission performance. (a) Chip structure and SEM image; (b) comparison of tested transmission performance

Fig. 6. PLC-based 1×16 splitter and demonstration of distributed free space optical frequency transfer. (a) Diagram of 1×16 splitter; (b) experimental setup for distributed free space optical frequency transfer; (c) tested results

Fig. 7. On-chip bidirectional frequency shifter based on LNOI platform and corresponding tested performance. (a) Chip structure diagram; (b) (c) chip SEM images; (d) packaged chip structure; (e) tested performance

Table 1. Research progress of fiber-optic time transfer

Table 2. Research progress of fiber-optic microwave frequency transfer

Table 3. Research progress of fiber-optic optical frequency transfer