Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Nonlinear interaction between spectral components in two different photonic bandgaps is experimentally demonstrated by launching femtosecond pulses near a zero-dispersion wavelength of a hybrid photonic crystal fiber, which guides by a combination of total internal reflection and bandgap effects. It is demonstrated that the initial pulse becomes spectrally broadened, and narrowband resonant radiation is generated in a different bandgap from the one responsible for guiding at the pump wavelength. The spectral intensity of the resonant radiation peaks at 2.7 dB below that of the broadened pulse in the pump-guiding bandgap. (C) 2008 Optical Society of America331820802082Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Danish High Technology FoundationFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)