Abstract
We demonstrate coherent multiphoton imaging of PbS colloidal quantum dots based on the detection of their transient resonant four-wave-mixing (FWM) emission under 150 fs pulsed laser excitation. Background-free imaging of PbS quantum dots in resonance with their ground-state excitonic absorption at $1.2\text{ }\ensuremath{\mu}\text{m}$ wavelength is shown, with intrinsic optical sectioning and a spatial resolution better than the one-photon diffraction limit, promising for deep tissue microscopy. The four-wave-mixing efficiency is found to be resonant to the ground-state absorption maximum, which is a prerequisite for spectral multiplexing. The measured FWM dynamics is consistent with the presence of charged exciton and biexiton Auger recombination in the 10--100 ps time scale, phonon-assisted exciton thermalization in the nanosecond time scale, and excitonic recombination in the microsecond time scale.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
