We compare the effects of spherical aberration on the penetration depth of single-photon and two-photon excitation for instances in which the aberration is caused by the refractive-index mismatch when a beam is focused through an interface. It is shown both theoretically and experimentally that two-photon fluorescence imaging experiences less spherical aberration and can thus propagate to a deeper depth within a thick medium.
© 2000 Optical Society of America
Djenan Ganic, Xiaosong Gan, and Min Gu, "Reduced Effects of Spherical Aberration on Penetration Depth Under Two-Photon Excitation," Appl. Opt. 39, 3945-3947 (2000)