Optical sectioning by multiexcitonic ladder climbing in colloidal quantum dots.
Optical sectioning is performed by collecting the fluorescent emission of two-exciton states in colloidal quantum dots. The two-exciton state is created by two consecutive resonant absorption events, thus requiring unprecedented low excitation energy and peak powers as low as 10(5) W/cm(2). The depth resolution is shown to be equivalent to that of standard multiphoton microscopy, and it was found to deteriorate only slowly as saturation of the two-exciton state is approached, owing to signal contribution from higher excitonic states.
Ben-Haim
Nir R
NR
Department of Physics of Complex Systems, Weizmann Institute of Science, Rehovot, Israel.
Oron
Dan
D