The main theoretical and experimental backgrounds of two-photon absorption (TPA) and TPA-induced free carriers in silicon are presented in detail. In particular, the mostly recent experimental achievements in applications of TPA and TPAinduced free carriers are discussed, such as optical limiting, optical pulse shaping, all-optical switching and modulation, alloptical logic gates, all-optical w...

We present a new approach to investigate how the photodynamics of an octahedral ruthenium(II) complex activated through two-photon absorption (TPA) differ from the equivalent complex activated through one-photon absorption (OPA). We photoactivated a Ru(II) polypyridyl complex containing bioactive monodentate ligands in the photodynamic therapy window (620-1000 nm) by using TPA and used transien...

We report a series of stiff dendrimers (referred to as T1, T2, T3, and T4) that have both gigantic two-photon absorption (TPA) cross sections up to 25,000 GM and strong two-photon excited fluorescence (TPEF) with fluorescence quantum yield of ∼0.5. The large TPA cross sections and high quantum yields of these dendrimers are directly related to their geometrical structures, where the polycyclic ...

We present a quantum chemical study of the two-photon absorption (TPA) properties of yellow fluorescent protein (YFP), a mutant of the extensively studied green fluorescent protein. The aromatic chromophore of YFP has a π-stacking interaction with the aromatic ring of a tyrosine residue (Tyr203) in a parallel-displaced structure with a distance of about 3.4 Å. We study the TPA spectrum of the π...

Porphyrin molecules have a highly conjugated cyclic structure and are theorized to have unusually large two-photon absorptivities (sigmaTPA), i.e., sigmaTPA approximately 10(2) GM. The authors tested this claim. Ultrafast two-photon absorption (TPA) spectroscopy was performed on solutions of hemoglobin, which contains a naturally occurring metaloporphyrin. They used a pump-probe technique to di...

The two-photon absorption (TPA) properties of two extended symmetric squaraine dyes are thoroughly characterized from the experimental and quantum-chemical point of view. The two molecules are specially engineered to have a multipolar structure with increasing complexity, D-π-A-π-D and A'-π-D-π-A-π-D-π-A', respectively. The experimental TPA spectra, measured by means of the Z-scan technique in ...

Laser Fault Injection (LFI) is considered to be the most powerful semiinvasive fault injection method for implementation attacks on security devices. In this work we discuss first time application of nonlinear Two-Photon Absorption (TPA) effect purpose LFI. Though TPA an established technique in other areas, e.g. fluorescence microscopy, so far it did not receive any attention field physical at...

Single photons are of paramount importance to future quantum technologies, including quantum communication and computation. Nonlinear photonic devices using parametric processes offer a straightforward route to generating photons, however additional nonlinear processes may come into play and interfere with these sources. Here we analyse spontaneous four-wave mixing (SFWM) sources in the presenc...

When a low flux of time-frequency-entangled photon pairs (EPP) illuminates two-photon transition, the rate absorption (TPA) can be enhanced considerably by quantum nature number correlations and frequency correlations. We present quantum-theoretic derivation entangled TPA (ETPA) calculate an upper bound on amount enhancement that is possible in such systems. The derived bounds indicate order to...