Intracavity Gain and Absorption Dynamics of Hybrid Modelocked Semiconductor Lasers using Multiple Quantum Well Saturable Absorbers

Abstract

Time resolved intracavity gain and saturable absorption dynamics, along with intracavity intensity pulse profiles and their corresponding spectrograms, were measured in an external cavity hybrid modelocked semiconductor diode laser. These measurements were performed to obtain fundamental information regarding the modelocking dynamics and to determine their role in the pulse shaping and chirping dynamics. The results of these experiments show that the integrating nonlinearity associated with gain depletion, coupled with group velocity dispersion, leads to asymmetric intensity pulse profiles with predominantly cubic temporal phase, while saturable absorption coupled with group velocity dispersion tends to linearize the chirp. Exploitation of these dynamics may allow researcher to generate optical pulses with higher peak intensities than previously reported.