Performance improvement of directly modulated semiconductor optical amplifier with filter‐assisted birefringent fiber loop

Abstract

ABSTRACTWe propose to use an optical bandpass filter (OBPF) placed after a birefringent fiber loop (BFL) to improve the performance of a semiconductor optical amplifier (SOA), which is directly modulated at an extended data rate than that enabled by its limited modulation bandwidth. The OBPF complements the BFL action by being detuned toward the opposite sideband than the BFL. The obtained experimental results demonstrate and confirm that compared with the BFL only, the filter‐assisted BFL scheme can further reduce the chirp and pulse peak amplitude variations, reshape the eye diagram, and make more symmetric and narrow the spectrum of the encoded data signal after the SOA. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2247–2251, 2015