Enhanced Properties in Single-Walled Carbon Nanotubes Based Saturable Absorber for All Optical Signal Regeneration
Résumé
Ultrafast relaxation dynamics of photogenerated carriers in nanostructure based saturable absorber (SA) are investigated using a degenerate cross-polarized pump--probe experiment at 1.55 μm operating wavelength. Single-walled carbon nanotubes (SWNT) encased in micelles are studied and compared to bundled ones as well as to iron doped InGaAs/InP multiple quantum wells (MQW). SA parameters for all optical signal regeneration (AOSR) are extracted from the normalized differential transmission. Although all samples show the same order of recombination time, SWNT in micelles present a much higher contrast ratio associated to a lower level of saturation fluence as compared to their bundled and MQW counterparts.