Directly modulated quantum-dash mode-locked lasers for millimeter-wave over fiber applications

Abstract

A directly modulated quantum dash mode-locked laser is proposed for a 50-GHz millimeter-wave over fiber architecture. This advancement offers enhanced fiber-wireless communication capabilities, facilitating coverage of 15-km SMF and 2m wireless QPSK transmissions. By utilizing the directly modulated laser (DML), we have successfully achieved an optical heterodyne mmW frequency of 50 GHz with exceptional stability. Notably, the measured RF beat-note 3-dB linewidth of the QDash DML is significantly reduced to 2.4 kHz, without the need for any optical feedback scheme. This DML-based hybrid architecture demonstrates the potential to seamlessly integrate with existing optical and wireless networks for next-generation indoor and short-reach mobile communications.