AVS 50th International Symposium
    Nanotubes Wednesday Sessions
       Session NT-WeA

Paper NT-WeA4
Infrared Stimulated Emission and Optical Gain in Isolated Single-Walled Carbon Nanotubes

Wednesday, November 5, 2003, 3:00 pm, Room 317

Session: Properties of Carbon Nanotubes
Presenter: M.S. Arnold, Northwestern University
Authors: M.S. Arnold, Northwestern University
J.E. Sharping, Northwestern University
S.I. Stupp, Northwestern University
P. Kumar, Northwestern University
M.C. Hersam, Northwestern University
Correspondent: Click to Email
Bandgap fluorescence from single-walled carbon nanotubes (SWNTs) isolated in surfactant micelles has recently been reported.@footnote 1@ Since semiconducting SWNTs possess electronic bandgaps in the near infrared region of the optical spectrum, these nanomaterials have potential application in fiber optic communication and infrared medical imaging. In this talk, we will discuss experimental results characterizing stimulated emission of infrared radiation from SWNTs isolated in aqueous micellar suspensions. Solutions of nanotubes are optically pumped at the E@sub 22@ transition for a particular (n, m) chirality, and stimulated emission is probed at the corresponding E@sub 11@ transition. The stimulated emission in isolated SWNT solutions is observed to be more than 122 times larger than in a control sample of aggregated SWNTs. Pump and probe power, wavelength, and polarization; path length; and concentration dependencies have been characterized. For small probe intensities, the stimulated emission intensity increases linearly with probe intensity, while sub-linear behavior is observed for large probe intensities; and gain and stimulated emission are maximized for co-linear-polarization of pump and probe. Currently, measurements are underway to quantify the gain coefficient and carrier lifetimes using delayed pulsed pump-probe spectroscopy. These results suggest the conditions under which tunable infrared optical amplification devices may be realized with SWNTs. @FootnoteText@ @footnote 1@ M. J. O'Connell et al., Science, 291, 2002.