P-i-n junction quantum dot saturable absorber mirror

We report on nonlinear optical properties of a p-i-n junction quantum dot saturable absorber based on InGaAs/GaAs. Absorption recovery dynamics and nonlinear reflectivity are investigated for different reverse bias and pump power conditions. A decrease in absorption recovery time of nearly two orders of magnitude is demonstrated by applying a voltage between 0 and-20 V. The saturable absorber modulation depth and saturation fluence are found to be independent from the applied reverse bias. © 2012 Optical Society of America.