Showing papers by "Lan Yang published in 2006"
TL;DR: In this paper, the authors used a tapered fiber coupling to reduce the threshold energy in the case of free space excitation to 9.9 fJ. The reason for the threshold reduction is attributed to the efficient delivery of pump pulses to the active gain region of the toroidal microcavity.
Abstract: Chemically synthesized nanocrystal, CdSe/ZnS (core/shell), quantum dots are coated on the surface of an ultrahigh-Q toroidal microcavity and the lasing is observed at room and liquid nitrogen temperature by pulsed excitation of quantum dots, either through tapered fiber or free space. Use of a tapered fiber coupling substantially lowered the threshold energy when compared with the case of free space excitation. The reason for the threshold reduction is attributed to the efficient delivery of pump pulses to the active gain region of the toroidal microcavity. Further threshold reduction was possible by quantum dot surface-coverage control. By decreasing the quantum dot numbers on the surface of the cavity, the threshold energy is further decreased down to 9.9 fJ.
91 citations
TL;DR: The capability to modify the spectral line shapes by tuning the coupling between or losses of two resonators may find applications in optical filtering, switching, sensing, and dispersion engineering.
Abstract: The transmission spectra of a Fabry-Perot etalon coupled to a microtoroid resonator are studied theoretically and experimentally. The resonance line shapes depend strongly on the resonance wavelength detuning and coupling strength between the two resonators. A wide variety of line shapes, ranging from a single to triple peaks, symmetric to asymmetric Fano-like peaks, and notches were predicted and observed experimentally. The capability to modify the spectral line shapes by tuning the coupling between or losses of two resonators may find applications in optical filtering, switching, sensing, and dispersion engineering.
58 citations
21 May 2006
TL;DR: In this article, the authors demonstrate an on-chip toroidal microcavity nanocrystal quantum dot laser with a threshold energy below 10 femto-Joules at room temperature.
Abstract: We demonstrate an on-chip toroidal microcavity nanocrystal quantum dot laser with a threshold energy below 10 femto-Joules at room temperature, a factor of 1 million lower than previously reported for strongly-confined, nanocrystal quantum dot lasers.