Localized surface plasmon resonance in the IR regime

Arrays of differently sized disk shaped gold nanoantennas are prepared on glass, which show localized surface plasmon resonance and Rayleigh anomalies in the near infrared and telecom range between 1000 and 1500 nm wavelength. The spectral position of these grating resonances depends critically on the period of the array and the size of the nanoantennas. When PbS quantum dots embedded in PMMA surround the nanoantennas, an up to four fold enhancement of the photoluminescence is observed at the grating resonances due to the constructive diffractive feedback among neighboring antennas. In accordance with the grating resonances a shift of the emission towards smaller wavelengths with decreasing disk diameter is demonstrated.