Open AccessTwo Photon Emission and Nonlinear Optical Imaging of Acetonitrile-Treated Quasi-Spherical Nanoscale PbS Systems
Author(s) -
N. Dutta,
D. Mohanta,
G. A. Ahmed,
A. Choudhury,
R. Hristu,
S. G. Stanciu,
G. A. Stanciu
Publication year - 2010
Publication title -
ieee photonics journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.725
H-Index - 73
eISSN - 1943-0655
pISSN - 1943-0647
DOI - 10.1109/jphot.2010.2093513
Subject(s) - engineered materials, dielectrics and plasmas , photonics and electrooptics
The fabrication and nonlinear optical imaging of ~ 5-nm-sized lead sulfide (PbS) nanoscale particles prepared in a water-soluble polymer matrix is reported. The two photon excitation fluorescence (TPEF) studies (using Ti:Sapphire laser, λex ~ 706 nm, P = 400 mW, pulse ~ 80 fs) clearly show the foremost band-edge and asymmetric trap-related emissions. The chain-like organization of PbS nanoparticles was evident from the electron microscopy studies, and the impression from a cluster of nanopatterns was observable through laser scanning confocal microscopy. We have observed adequate correspondence between the TPEF spectra-based nonlinear optical images and spots corresponding to PbS nanoparticle assemblies. In addition, the PbS nanoparticles that are capable of producing strong second harmonic signals were efficiently imaged along the forward direction of the nonlinear microscopy. Investigation of two photon absorption processes along with the second-harmonic-generated imaging indicates the possibility of using the nanoscale particles in single molecule fluorescence spectroscopy, biomolecular labeling, and/or imaging applications.