Electronic energy dissipation in chloro-aluminum phthalocyanine/methanol system following nonlinear interaction with a train of picosecond pulses
Using the Z-scan technique, we study the nonlinear interaction of a dilute methanolic solution of chloro-aluminum phthalyocyanine with a ∼70 ns long train of laser pulses, each of 18 ps duration. The observations are explained by taking into account, in addition to the photoexcitation of a ground state molecule by a single pulse, thermal lensing and photoabsorption by an excited molecule (singlet or triplet) produced by previous pulses. A microscopic picture of the heating process in the solution is provided.
An approach for modeling of planar microwave filters by the Method of Lines (MoL) is presented. The algorithm combines 2-D discretization of the cross-section with the numerically stable impedance/admittance transformation. To improve accuracy and efficiency of this approach, edge conditions are examined and the best edge position relative to the discretization lines is derived. The convergence behaviour of the method for different edge positions is examined. To substantiate the proposed formulation three planar microwave filter are modeled.