Abstract
We use time-resolved degenerate four-wavemixing (DFWM) with femtosecond pulses in the wavelength range 0.74−1.7 μm to measure both phase and amplitude of all nonvanishing elements of the electronic third-order nonlinear optical susceptibility tensor cijkl(−ω,ω,ω,−ω) of a 10 μm amorphous C60 film on a CaF2 substrate. Linear absorption is found to be less than 1% in this range. We find a single resonance in DFWM, the amplitudes and phases of which are fit well by a Lorentzian model of a two-photon resonance to a level 2.7 ± 0.1 eV above the ground level, with width 0.25 eV. The peak two-photon absorption coefficient is 0.02 cm/MW, essentially the same peak value as for bulk gallium arsenide, one of the strongest and most widely studied of the two-photon absorbers. Our results show there is only one two-photon allowed transition below 3.4 eV (as well as below the first one-photon transition), an unambiguous signature which is expected from theory. Theory assigns the symmetry Hg to this lowest lying two-photo...
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.
