Tm3+/Ho3+ codoped tellurite fiber laser

Continuous-wave and Q-switched lasing from a Tm 3+ /Ho 3+ codoped tellurite fiber is reported. An Yb 3+ /Er 3+ -doped silica fiber laser operating at 1.6μm was used as an in-band pump source, exciting the Tm 3+ ions into the F 4 3 level. Energy is then nonradiatively transferred to the upper laser level, the I 7 5 state of Ho 3+ . The laser transition is from the I 7 5 level to the I 8 5 level, and the resulting emission is at 2.1μm . For continuous wave operation, the slope efficiency was 62% and the threshold 0.1W ; the maximum output demonstrated was 0.16W . Mechanical Q switching resulted in a pulse of 0.65μJ energy and 160ns duration at a repetition rate of 19.4kHz

Investigation of refractory dielectric for integrated circuits Second quarterly report, Dec. 1968

Process development for chemical deposition of aluminum oxide films as refractory dielectrics for integrated circuit

Investigation of refractory dielectric for integrated circuits Third quarterly report, Feb. 1969

Research and development on refractory dielectrics for integrated circuit

Effects of transient creep strain on post-tensioned concrete slabs in fire

Effects of transient creep strain of concrete on post-tensioned (PT) concrete slabs in fire are investigated by the approach of numerical modelling. Three-dimensional (3D) nonlinear finite element (FE) models were established employing the commercial package ABAQUS. Thermal creep strain of prestressing steel tendons was explicitly incorporated into the FE models. Three concrete constitutive models were considered including (a) the Basic Model without considering transient creep strain, (b) the Transient Model explicitly considering transient creep strain, and (c) the EC2 Model implicitly considering transient creep strain taken from BS EN 1992-1-2 (2004). Through comparing the numerical results with those obtained from available tests in the literature, excellent agreement was achieved, based on which the FE model with the Basic Model was verified at ambient temperature, and those with both the EC2 Model and Transient Model were verified as well in test fire scenarios. Conclusions are finally drawn with the emphasis that transient creep strain should be considered either explicitly or implicitly in numerical modelling for its positive contribution to the fire resistance of slabs.published_or_final_versio

Long-range surface plasmon polariton excitation at the quantum level

We provide the quantum mechanical description of the excitation of long-range surface plasmon polaritons (LRSPPs) on thin metallic strips. The excitation process consists of an attenuated-reflection setup, where efficient photon-to-LRSPP wavepacket-transfer is shown to be achievable. For calculating the coupling, we derive the first quantization of LRSPPs in the polaritonic regime. We study quantum statistics during propagation and characterize the performance of photon-to-LRSPP quantum state transfer for single-photons, photon-number states and photonic coherent superposition states.Comment: 9 pages, 6 figures, RevTeX4; Accepted versio