Femtosecond gain and index dynamics in an InAs/InGaAsP quantum dot amplifier operating at 1.55 microm.
We report on the characterization of the ultrafast gain and refractive index dynamics of an InAs/InGaAsP self-assembled quantum dot semiconductor optical amplifier (SOA) operating at 1.55 mum through heterodyne pump-probe measurements with 150 fs resolution. The measurements show a 15 ps gain recovery time at a wavelength of 1560 nm, promising for ultrafast switching at >40 GHz in the important telecommunications wavelength bands. Ultrafast dynamics with 0.2-1.5 ps lifetimes were also found consistent with carrier heating and spectral hole burning. Comparing with previous reports on quantum dot SOAs at 1.1-1.3 mum wavelengths, we conclude that the carrier heating is caused by a combination of free-carrier absorption and stimulated transition processes.
Zilkie
Aaron J
AJ
Meier
Joachim
J
Smith
Peter W E
PW
Mojahedi
Mo
M
Aitchison
J Stewart
JS
Poole
Philip J
PJ
Allen
Claudine Nì
CN
Barrios
Pedro
P
Poitras
Daniel
D