Femtosecond two-photon absorption measurements based on the accumulative photo-thermal effect and the Rayleigh interferometer.
A rapid, straightforward method for measuring the two-photon absorption cross sections in liquid samples based on both the accumulative photo-thermal effect and the Rayleigh interferometery is described and demonstrated. This technique combines the sensitivity of the thermal lens approach and the accuracy of interferometry techniques. Focusing a high repetition rate laser beam in the sample, generating a localized change in its refractive index, induces the photo-thermal phase shift. By recording and processing two interference patterns, this technique allows the rapid estimation of the two-photon absorption cross section of the sample. Significantly, the experimental results demonstrate that this new method can be used with both fluorescent and non-fluorescent samples.
Rodriguez
Luis
L
Department of Chemistry, The College of Optics and Photonics, University of Central Florida, PO Box 162366, Orlando, Florida 32816-2366, USA.
Ahn
Hyo-Yang
HY
Belfield
Kevin D
KD
D017076:Computer-Aided Design; D004867:Equipment Design; D019544:Equipment Failure Analysis / Q000379:methods*; D007368:Interferometry / Q000295:instrumentation*; D008027:Light; D036641:Microscopy, Fluorescence, Multiphoton / Q000295:instrumentation* / Q000379:methods*; D017785:Photons; D015203:Reproducibility of Results; D012542:Scattering, Radiation; D012680:Sensitivity and Specificity