Observation of enhanced two photon absorption in ZnS quantum dots at an ultravio

Two-photon absorption (2PA) in zinc sulphide (ZnS) and Mn2+-doped ZnS quantum dots is reported by the z-scan technique, with nanosecond pulsed laser radiation at 355 nm. The observed values of the 2PA cross section of all the samples are 105 times larger than that of bulk ZnS.