A technique that determines the alteration in the
refractive index of a medium as a result of the temperature rise in the path of a
laser beam absorbed by the medium. The lens produced (usually divergent) causes a change
(usually a decrease) in the irradiance measured along the
laser beam axis.
Source:
PAC, 1996, 68, 2223
(Glossary of terms used in photochemistry (IUPAC Recommendations 1996))
on page 2279