Qianjin Shu

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  • B Abbott, R Abbott, +401 authors A G Lyne
  • Physical review letters
  • 2005
We place direct upper limits on the amplitude of gravitational waves from 28 isolated radio pulsars by a coherent multidetector analysis of the data collected during the second science run of the LIGO interferometric detectors. These are the first direct upper limits for 26 of the 28 pulsars. We use coordinated radio observations for the first time to build(More)
We report on a novel high-sensitivity method to characterize and improve mode matching into optical cavities. This method is based on heterodyne detection of cylindrical transverse cavity modes. A specially designed annular-segmented photodiode is used to measure the amplitude of nonresonant modes reflected by the cavity. Our measurements allow us to(More)
A gain of 22 times was obtained by nondegenerate two-wave mixing in Cr:YAlO(3). To our knowledge, this is the largest cw two-wave mixing gain obtained in a bulk solid-state nonphotorefractive material. The measured gain appears to be limited by beam breakup that is due to spatial nonuniformities in the nonlinear refractive-index change that are the result(More)
In this article, we present a simple design method for the plate foundation of a transmission tower in a mining area, which is based on the theory of beam rested on an elastic foundation. The corresponding theoretical model has been developed with the synergistic reaction of a composite protection plate by considering the mining subsidence of ground. On the(More)
The performance of resisting foundation displacement of typical single return circuit and double return circuit transmission towers under all kinds of load conditions including foundation horizontal displacement, foundation vertical uneven downward displacement were analyzed by finite element modeling. Results showed that stability failure of single steel(More)
Two-beam coupling measurements of an avalanche upconversion transition in concentrated Tm:LiYF (4) confirm that, despite the resonant nature of the excited-state optical interaction, the induced response is strongly dispersive. This surprising characteristic is shown to be a general feature of avalanche polarization, with an off-resonant process dominating(More)
We report an essentially complete characterization of energies and relaxation processes of the lowest seven electronic states of the N-V (nitrogen-vacancy) center in diamond using several different nonlinear laser spectroscopic techniques. We have also applied ultrafast optical techniques to measure dielectric properties of CVD and bulk diamond in the(More)
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