Pulse compression using chirp of transistor lasers regardless of types of fiber dispersions

The transistor laser (TL) is a device with features of both the heterojunction bipolar transistor and diode laser (DL) [1]. Its optical output can be modulated by the base-collector junction voltage due to the Franz-Keldysh (FK) effect [2-4]. By varying the BC voltage, both the absorption in BC junction and gain in active region are changed. These induce a frequency chirp different from those of DLs [5]. The chirp is neither positive nor negative, which induces the pulse compression in both types of fibers with normal and anomalous dispersions. ? 2019 IEEE