We measured the absorption spectrum (340-640 nm) of the
purest water available with photothermal deflection spectroscopy.
Our spectrum exhibits an absorption minimum in the blue region of
the specturm that is deeper than in most previously documented
pure-water absorption studies. We attribute this to exceptional
sample purity and our techniques's inherent freedom from
scattering effects. Because the absorption minimum is
significantly lower, our spectrum displays high-order molecular
resonance structure not observed in any previous absorption
studies to our knowledge. We find the minimum in the absorption
specturm of pure water is 0.0062±0.0006 m-
1 at 420 nm and 25°. }
F. M. Sogandares, E. S. Fry, "Absorption spectrum (340-
640 nm) of pure water. I. Photothermal Measurements,"
Appl. Opt.,36, 8699-8709, (1997).