Nonlinear optics has been the subject of intensive research because of its wide applications in field of photonics, nanophotonics [1] and optoelectroncs such as optical signal processing, broad-band optical communicat...Nonlinear optics has been the subject of intensive research because of its wide applications in field of photonics, nanophotonics [1] and optoelectroncs such as optical signal processing, broad-band optical communications, integrated optics, optical sensing, optical poling, optical limiting, optical computing etc. A common problem in the laser technology is the protection of human eye and optical sensors from the damaging effects of high-energy light. Passive optical limiters can be the solution of this kind of problems.So optical materials with large coefficients of TPA and nonlinear refraction are of prime importance in optical limiting applications. Recently the C_ 60-TTF have attracted much attention because of their three-dimensional π-electron conjugated systems which makes them promising as new limiting materials [2]. Two-photon absorption, second harmonic generation (SHG), detection of phase transition using photoinduced nonlinear effects and illustration of new system for optical recording and erasing of holograms under weak laser illumination will be discussed. In other hand a series of new Donor-π-Acceptor ruthenium acetylide systems built around thiophene-based π-conjugating spacers has been developed and studied, in terms of the oligothienyl chain length. Comparison of the linear and third-order nonlinear optical properties of these Donor-π-Acceptor chromophores shows that the elongation of the spacer and introduction of a double bond in this spacer produces a considerable bathochromic shift of the absorption maximum together with a dramatic enhancement of the molecular cubic hyperpolarizability in these systems. Finally, acoustically induced second harmonic generation (AISHG) has been observed for thin films of these complexes incorporated in PMMA matrices, which reaches values among the highest, reported so far.展开更多
文摘Nonlinear optics has been the subject of intensive research because of its wide applications in field of photonics, nanophotonics [1] and optoelectroncs such as optical signal processing, broad-band optical communications, integrated optics, optical sensing, optical poling, optical limiting, optical computing etc. A common problem in the laser technology is the protection of human eye and optical sensors from the damaging effects of high-energy light. Passive optical limiters can be the solution of this kind of problems.So optical materials with large coefficients of TPA and nonlinear refraction are of prime importance in optical limiting applications. Recently the C_ 60-TTF have attracted much attention because of their three-dimensional π-electron conjugated systems which makes them promising as new limiting materials [2]. Two-photon absorption, second harmonic generation (SHG), detection of phase transition using photoinduced nonlinear effects and illustration of new system for optical recording and erasing of holograms under weak laser illumination will be discussed. In other hand a series of new Donor-π-Acceptor ruthenium acetylide systems built around thiophene-based π-conjugating spacers has been developed and studied, in terms of the oligothienyl chain length. Comparison of the linear and third-order nonlinear optical properties of these Donor-π-Acceptor chromophores shows that the elongation of the spacer and introduction of a double bond in this spacer produces a considerable bathochromic shift of the absorption maximum together with a dramatic enhancement of the molecular cubic hyperpolarizability in these systems. Finally, acoustically induced second harmonic generation (AISHG) has been observed for thin films of these complexes incorporated in PMMA matrices, which reaches values among the highest, reported so far.
