Third-order NLO properties of ultrathin films containing cationic phthalocyanine and Keggin polyoxometalates fabricated using layer-by-layer deposition from aqueous solution

Third-order optical nonlinearities of ultrathin films derived from cationic phthalocyanine and Keggin polyoxometalates can be well tuned and enhanced.

Enhanced reverse saturable absorption of electrostatic self-assembled layer by layer films containing (8-quinolineoxy-5-sulfonic acid)phthalocyanine cobalt and graphene oxide

The 25-bilayer CoPc/GO film was fabricated through electrostatic self-assembled layer by layer (LBL) technique, and it exhibits strong reverse saturable absorption (RSA) effect with the input intensity of 1.16 μJ.

Excited-state enhancement of third-order optical nonlinearities: photodynamics and characterization

Based on the simplified five-level rate-equation theory, we investigate the hybrid third-order optical nonlinear processes which combine the instantaneous nonlinearity and the one-photon absorption induced excited-state nonlinearity. We obtain the analytical third-order nonlinear absorption and refraction coefficients originating from the singlet and triplet excited-state effects. We explore the photodynamic process and give the corresponding level diagram in the nanosecond, picosecond, and femtosecond regimes. We develop the pulse-duration-dependent Z-scan theory for characterizing the simultaneous instantaneous nonlinearity and cumulative effect of the excited-state nonlinearity. We also demonstrate the validity of the presented theory to analyze the experimental results.