Optimizing two-photon absorption for volumetric optical data storage

Alternative selection rules for one- and two-photon transitions in tribenzotetraazachlorin: Quasi-centrosymmetrical π-conjugation pathway of formally non-centrosymmetrical molecule

“…[5][6][7][8] These molecules are very attractive for applications based on nonlinear absorption, such as optical power limiting, 9,10 high-density volumetric data storage, 11,12 and deep tissue photodynamic therapy. 13,14 We have recently studied the 2PA spectra of a series of symmetrically substituted Pcs, and found strong, gerade-gerade (g-g) 2PA transitions in the energy region between the Q-and B-bands.…”

Influence of blue valence absorption band on nonlinear absorption in dysprosium bisphthalocyanine studied by open aperture z-scan

“…These macroheterocyclic compounds demonstrate very high thermal, chemical and photochemical stability and have been used in various applications in technology and material science. Pcs have been utilized as photovoltaic elements in solar cells [1], gas sensors [2,3], organic field-effect transistors [4], optical data storage materials [5]. In optics Pcs are of the great interest on account of their high pronounced nonlinear optical properties [6,7].…”

Modeling non-Lorentzian two-photon absorption line shape in dipolar chromophores

“…To satisfy this condition, the two-photon laser wavelength is tuned as far towards longer wavelengths as possible, until the 1PA background resulting from the lowestenergy transition becomes small, and the quadratic intensity dependence is established [1]. However, in some demanding practical tasks, such as deep tissue two-photon fluorescence microscopy and 2PA-based 3-D high density optical memory, it is essential to take into account excitation of both 1PA as well as 2PA transitions, especially if near-resonance enhancement is used to increase the efficiency of 2PA [2]. This, in turn, requires quantitative characterization of the involved homogeneous-and inhomogeneous linear-and nonlinear line shapes.…”

“…in the case of step-wise process leading to reverse saturable absorption [7,8]. However, if the excitation laser frequency is detuned far from the one photon resonance, then to realistically estimate the relative rate of 2PA versus 1PA transitions one needs a quantitative model of the 1PA and 2PA line shapes [2,9]. In this paper we present a new approach to modeling of homogeneous line shape in 2PA spectra using numerical solution of stochastic two-level density matrix equation of motion.…”