We have developed an optical phase-locked loop (OPLL) that can operate over 500km. The coherent transmitter is a 1.54μm 13C2H 2 frequency-stabilized CW fiber ring laser with a frequency stability of 2.0 × 10-11 and a linewidth of 4kHz. To obtain wide band operation with a bandwidth of 1 GHz, we fabricated a high-speed fiber laser as a local oscillator. By using these fiber lasers, the OPLL circuit successfully generated an intermediate frequency signal with a phase error variance of 7.9 × 10-3 rad.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering