Time-domain evidence for spectral hole burning in an InGaAsP optical amplifier

W. E. Moerner, Wilfried Lenth, Gary C. Bjorklund

W. E. Moerner, M. D. Levenson, Peter Pokrowsky +1 more

Wilfried Lenth, W. E. Moerner

Aaron J. Zilkie, J. Meier, Peter W. E. Smith +6 more

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.

Stefan Putz, Andreas Angerer, Dmitry O. Krimer +5 more

Alessandro D’Ottavi, Eugenio Iannone, Antonio Mecozzi +5 more

Measurements of four-wave mixing in traveling wave semiconductor optical amplifiers are extended up to frequency detunings between pump and probe as high as 4.3 THz. The 35 fs equivalent time resolution is, to our knowledge, the highest achieved to date. Experimental evidence of nonlinear processes faster than spectral hole burning is obtained for the first time by using a frequency domain technique.