Publication Date:
2019-07-12
Description:
Direct measurements are reported of the excited singlet-state absorption cross section and the associated nonlinear refractive cross section using picosecond pulses at 532 nm in solutions of phthalocyanine and naphthalocyanine dyes. By monitoring the transmittance and far-field spatial beam distortion for different pulsewidths in the picosecond regime, it is shown that both the nonlinear absorption and refraction are fluence (energy-per-unit-area) rather than irradiance dependent. Thus, excited-state absorption is the dominant nonlinear absorption process, and the observed nonlinear refraction is also due to real population excitation.
Keywords:
ATOMIC AND MOLECULAR PHYSICS
Type:
Applied Physics B - Photophysics and Laser Chemistry (ISSN 0721-7269); B 54; 46-51
Format:
text
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