Abstract
In the last decade, different solutions were proposed to boost the transmission bitrate of semiconductor lasers. Here, we focus on applying optical feedback to a semiconductor laser from an external cavity in order to induce enhancement of the modulation bandwidth up to 50 GHz as well as resonant modulation (RM) around frequencies approaching 60 GHz. High-speed modulation up to 90 Gbps under none-return to zero operation and a 45 Gbaud using pulse amplitude modulation-4 signals are predicted. Both types of improving the modulation performance of the laser are attributed to the photon-photon resonance (PPR) effect. The regimes of the external power reflectivity that correspond to both types of modulation response are specified. Comprehensive simulations are introduced to correlate the PPR frequency to the RM frequencies of the non-modulated coupled-cavity laser. Dependencies of the enhanced BW and PPR frequency on the cavity length and bias current are elucidated.