Two-photon absorption based optical limiting and stabilization by using a CdTe quantum dot solution excited at optical communication wavelength of ∼1300 nm

This letter presents the results of two-photon study of CdTe quantum dots (QDs) in chloroform. The measured two-photon absorption (2PA) spectrum shows that 2PA coefficient at ∼1300 nm is ∼0.02 cmGW. Based on a 1 cm path-length CdTe QD solution sample of 8 mgml concentration, irradiated by a focused ∼1300 nm laser beam of ∼160 fs duration, the nonlinear transmission could be changed from ∼100% to ∼20% when the input pulse energy was varied from ∼50 nJ to ∼10 μJ, demonstrating a superior optical limiting performance. The input laser fluctuation was significantly reduced after passing through the sample, indicating a remarkable optical stabilization behavior.