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We demonstrate digital tuning of the slow-light regime in silicon photonic-crystal waveguides by performing atomic layer deposition of hafnium oxide. The high group-index regime was deterministically controlled ͑redshift of 140Ϯ 10 pm per atomic layer͒ without affecting the group-velocity dispersion and third-order dispersion. Additionally, differential(More)
We present the first time-resolved cryogenic observations of Fö rster energy transfer in large, monodisperse lead sulfide quantum dots with ground-state transitions near 1.5 µm (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(More)
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(More)
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 ∼ 30 mW laser powers. Over this tuning(More)
In this letter, we propose the use of the newly developed corrugated quantum well infrared photodetectors ͑C-QWIPs͒ for polarization detection. The corrugated structure, which serves as an optical coupler as well as the polarization-sensitive component, is in this case directly created into the active region of the QWIP, therefore dispensed with the need of(More)
Despite the rapid development of the quantum well ͑QW͒ infrared technology, the intrinsic properties of the QW infrared photodetectors ͑QWIPs͒ have not been directly measured under the operating conditions of the detector. In this work, we introduce a characterization technique, which utilizes the surface corrugation to probe the absorption coefficient and(More)
In a quantum-grid infrared photodetector ͑QGIP͒, the active multiple quantum well material is patterned into a grid structure. The purposes of the grid are, on the one hand, to create additional lateral electron confinement and, on the other, to convert part of the incident light into parallel propagation. With these two unique functions, a QGIP allows(More)
In this letter we introduce a quantum well infrared photodetector ͑QWIP͒ structure, which we refer to as the quantum grid infrared photodetector ͑QGIP͒. In an ideal structure, a grid pattern with very narrow linewidth is created in the QWIP active region to achieve lateral electron confinement, thereby improving its absorption as well as transport(More)
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