Two-photon absorption spectra of fluorescent isomorphic DNA base analogs

Two-photon-induced fluorescence of isomorphic nucleobase analogs.

Five isomorphic fluorescent uridine mimics have been subjected to two-photon (2P) excitation analysis to investigate their potential applicability as non-perturbing probes for the single-molecule detection of nucleic acids. We find that small structural differences can cause major changes in the 2P excitation probability, with the 2P cross sections varying by over one order of magnitude. Two of...

Two-photon absorption spectra of carotenoids compounds

Non-Condon Effects in the One- and Two-Photon Absorption Spectra of the Green Fluorescent Protein

We report calculations of one and two photon absorption (OPA and TPA, respectively) spectra of the green fluorescent protein (GFP) chromophore using the doubleharmonic parallel-mode approximation and including explicit dependence of the electronic transition moments on nuclear geometry. The non-Condon effects are found to be more significant for TPA resulting in a different shape of the spectra...

Non-degenerate Two Photon Absorption Spectra of Si Nanocrystallites

The two-photon absorption (TPA) spectrum is an important optical property of semiconductors. It brings valuable information complementary to the one-photon absorption spectrum, gives the limits to the optical transparency of materials, and causes laserinduced damages. Recently, the TPA spectrum of direct-gap nanocrystallites was calculated by Cotter et al. [1] by using the effective-mass approx...

Fluorescent two-photon nanolithography.

Improving the excitation conditions in two-photon fluorescent lithography reduces the size of the fabricated structures to nanometre scales. We demonstrate that a precise control of the illumination profile and the scanning speed of the laser beam is enough to decrease the photo-polymerization volume of resins by orders of magnitude. This work also shows experimental evidence of surface effects...