Ultrashort Pulse Generation Using Cavity-Dumping in a Fano Laser

On-chip pulsed lasers with ultrashort pulse width and high peak power are required for many chip-scale applications, such as optical communication and optical computing. So far, pulse generation in semiconductor lasers has been demonstrated using a number of different physical mechanisms, including gain switching, Q-switching, and mode-locking [1]. Recently, a novel microscopic pulsed laser based on cavity dumping was demonstrated [2]. The scheme is based on the Fano laser [3], in which one of the mirrors is formed by an optical Fano resonance [4], and has the feature that it can easily be modulated [2]. In the experiment, however, the width of the generated pulses was limited by the relatively long carrier lifetime of the InP-based photonic crystal nanocavity [5]. Here, we present a theoretical analysis of the dynamics of pulse generation based on cavity dumping in the Fano laser and show the ability to generate pulses of width down to 1 ps, even in the presence of a long carrier lifetime (100 ps) in nanocavity.