Coherently wavelength injection-locking a 600-μm long cavity colorless laser diode for 16-QAM OFDM at 12 Gbit/s over 25-km SMF

• DOI: 10.1364/oe.21.016722
• Publication Date: 2013-07-05T18:59:59Z
• Authors: Yi-Cheng Li; Yu-Chieh Chi; Min-Chi Cheng; I-Cheng Lu; Jason Chen; Gong-Ru Lin
• Keywords: Laser diode; Extinction ratio

The coherent injection-locking and directly modulation of a long-cavity colorless laser diode with 1% end-facet reflectance weak-resonant longitudinal modes is employed as an universal optical transmitter to demonstrated for 16-QAM OFDM transmission at 12 Gbit/s over 25 km in DWDM-PON system. optimized bias current 30 mA (~1.5Ith) corresponding extinction ratio (ER) 6 dB the external injection power -9 dBm (are) required such wavelength-locked carry 122-subcarrier formatted data-stream. By increasing from 0 dBm, peak-to-peak chirp data stream reduces 7.7 5.4 GHz. side mode suppression (SMSR) up 50 achieved wider detuning range between -0.5 nm 2.0 under dBm. modulating 122 subcarriers central carrier frequency 1.5625 GHz total bandwidth 3 GHz, rate standard single-mode fiber achieve error vector magnitude (EVM) 5.435%. Such can deliver data-stream QAM-OFDM after 25-km receiving sensitivity -7 BER 3.6 × 10(-7) when pre-amplifying by 5 dB.