Translator Disclaimer
10 March 2015 Optical bandwidth broadening in two-section passively mode-locked InAs quantum dot lasers in the random population regime
Author Affiliations +
Proceedings Volume 9382, Novel In-Plane Semiconductor Lasers XIV; 93820C (2015) https://doi.org/10.1117/12.2079352
Event: SPIE OPTO, 2015, San Francisco, California, United States
Abstract
Optical emission spectra, optical puslewidths and optical gain spectra are compared as a function of temperature using different sections of gain length for a passively mode-locked InAs quantum dot device. By increasing the length of the gain section, we decrease the threshold condition for mode-locking which allows access to a greater gain bandwidth. At 300 K, when the dots states and wetting layer are in thermal equilibrium, a decrease in the threshold condition results in little change in the width of the optical emission spectra and the corresponding optical pulsewidths. At 80 K, where the dot states are randomly populated, the same decrease in the threshold condition, results in a near doubling of optical emission spectra and a reduction in the optical pulsewidth from 910 fs to 600 fs. These changes in pulsewidth were obtained with only a modest 20% reduction of threshold condition from 14 cm-1 to 11 cm-1 which corresponds to an increase of the gain section length from 2 mm to 2.6 mm. The experimental results are qualitatively explained using a simple set of rate equations, which take explicit account of the photon density in the cavity. A reduction in the cavity loss results in an increase in the width of the gain spectrum at and above threshold as dots of different sizes in the inhomogeneous distribution are no longer coupled via carrier escape to the wetting layer.
© (2015) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
P. Finch, M. Hutchings, P. Blood, P. M. Smowton, Angela D. Sobiesierski, and I. O'Driscoll "Optical bandwidth broadening in two-section passively mode-locked InAs quantum dot lasers in the random population regime", Proc. SPIE 9382, Novel In-Plane Semiconductor Lasers XIV, 93820C (10 March 2015); https://doi.org/10.1117/12.2079352
PROCEEDINGS
10 PAGES


SHARE
Advertisement
Advertisement
Back to Top