Using optical pump-white light probe spectroscopy the gain dynamics is investigated for a VECSEL chip which is based on a type-II heterostructure. The active region the chip consists of a GaAs/(GaIn)As/Ga(AsSb)/(GaIn)As/GaAs multiple quantum well. For this structure, a fully microscopic theory predicts a modal room temperature gain at a wavelength of 1170 nm, which is confirmed by experimental spectra. The results show a gain buildup on the type-II chip which is delayed relative to that of a type-I chip. This slower gain dynamics is attributed to a diminished cooling rate arising from reduced electron-hole scattering.
@article{arxiv.1608.05250,
title = {Gain spectroscopy of a type-II VECSEL chip},
author = {Christian Lammers and Markus Stein and Christian Berger and Christoph Möller and Christian Fuchs and Antje Ruiz Perez and Arash Rahimi-Iman and Jörg Hader and Jerome Moloney and Wolfgang Stolz and Stephan W. Koch and Martin Koch},
journal= {arXiv preprint arXiv:1608.05250},
year = {2016}
}