Details

Objective and Scope of the Work: This research project is focused on experimentally investigating the feasibility of transmitting high-stability synchronization signals, generated by a rubidium atomic clock, through an optical fiber using a laser-based communication channel. The motivation behind this work lies in the need for precise time and frequency distribution over medium and long distances, especially in modern metrology, navigation, and communication systems. The study began with the construction of a complete laboratory setup that includes Fabry-Perot semiconductor lasers, optical fibers, high-speed photodetectors, and essential measurement instrumentation. The system was designed to support modulation-based transmission of clock signals and to allow the monitoring of waveform integrity and frequency stability at different transmission lengths. The experimental phase consisted of transmitting rubidium clock signals through fibers of two lengths: 1.5 meters and 5 kilometers. The quality of signal transmission was assessed by examining waveform fidelity and analyzing frequency stability through Allan deviation. Even after 5 km of fiber transmission, the results demonstrated good signal integrity and relatively low attenuation (~0.76 dB). Allan deviation measurements showed that frequency stability remained within acceptable levels, particularly after the system reached thermal equilibrium. Notably, the experiments also highlighted the importance of system warm-up and thermal stabilization. Cold-start conditions and incomplete warm-up led to increased short-term instability and transient noise. Repeated measurements showed that frequency performance gradually improved with continued operation, suggesting that passive thermal settling plays a crucial role in ensuring reliable transmission. Overall, the study confirms the feasibility of using a low-cost, fiber-based laser communication setup for transmitting atomic clock signals over long distances. The findings provide valuable experimental data and technical insights for the future development of robust optical synchronization systems in both research and applied contexts.