ABSTRACT
We examine the cavity resonance tuning of high-Q silicon photonic crystal heterostructures by localized laser-assisted thermal oxidation using a 532 nm continuous wave laser focused to a 2.5 µm radius spot-size. The total shift is consistent with the parabolic rate law. A tuning range of up to 8.7 nm is achieved with â¼ 30 mW laser powers. Over this tuning range, the cavity Qs decreases from 3.2×10(5) to 1.2×10(5). Numerical simulations model the temperature distributions in the silicon photonic crystal membrane and the cavity resonance shift from oxidation.
Subject(s)
Crystallization/methods , Nanotechnology/methods , Optics and Photonics/methods , Silicon Dioxide/chemistry , Silicon/chemistry , Crystallization/instrumentation , Finite Element Analysis , Lasers , Microscopy, Electron, Scanning , Models, Theoretical , Nanostructures , Nanotechnology/instrumentation , Optics and Photonics/instrumentation , Oxidation-Reduction , Temperature , Water/chemistryABSTRACT
We present the first time-resolved cryogenic observations of Forster energy transfer in large, monodisperse lead sulfide quantum dots with ground-state transitions near 1.5 microm (0.8 eV), in environments from 160 K to room temperature. The observed temperature-dependent dipole-dipole transfer rate occurs in the range of (30-50 ns) (-1), measured with our confocal single-photon counting setup at 1.5 microm wavelengths. By temperature-tuning the dots, 94% efficiency of resonant energy transfer can be achieved for donor dots. The resonant transfer rates match well with proposed theoretical models.
