Enhancement of two-photon excited fluorescence in two-dimensional nonlinear optical polymer photonic crystal waveguides

We examined two-photon excited fluorescence (TPEF) in two-dimensional highly nonlinear optical polymer photonic crystal waveguides with metallic cladding. A large TPEF enhancement of approximately two orders of magnitude was observed, originating from resonance between the external pump laser field and a photonic band mode. The results for TPEF enhancement are in good agreement with experimental photonic band resonances obtained by angle- resolved reflectivity measurements and the theoretical photonic band structure generated by three-dimensional finite-difference time-domain calculations, indicating that it is possible to use band dispersion control to design artificial nonlinear two-photon excitation processes. (C) 2008 American Institute of Physics.