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Amzajerdian F. Analysis of optimum heterodyne receivers for coherent lidar applications.; 2002.
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Ito H. High frequency photodiode work in Japan.; 2002.
Abstract: The recent progress in the device performance of the uni-traveling-carrier photodiode (UTC-PD) is described. The UTC-PD utilizes only electrons as the active carriers, and this unique feature is the key to achieving excellent high-speed and high-output characteristics simultaneously. The achieved performance includes a record 3-dB bandwidth of 310 GHz, high-power photonic millimeter-wave generation with an output power of over +13 dBm at 100 GHz, high-output-voltage photoreceiver operation at bit rates of up to 80 Gbit/s, and demultiplexing operation at 200 Gbit/s using a monolithic PD-EAM optical gate.
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Deang J, Du Q, Gunzburger MD. Modeling and computation of random thermal fluctuations and material defects in the Ginzburg–Landau model for superconductivity. J. Comp. Phys.. 2002;181(1):45–67.
Abstract: It is well known that thermal fluctuations and material impurities affect the motion of vortices in superconductors. These effects are modeled by variants of a time-dependent Ginzburg-Landau model containing either additive or multiplicative noise. Numerical computations are presented that illustrate the effects that noise has on the dynamics of vortex nucleation and vortex motion. For an additive noise model with relatively low variances, it is found that the vortices form a quasi-steady-state lattice in which the vortex core sizes remain roughly fixed but their positions vibrate. Two multiplicative noise models are considered. For one model having relatively long-range order, the sizes of the vortex cores vary in time and from one vortex to another. Finally, for the additive noise case, we show that as the variance of the noise tends to zero, solutions of the stochastic time-dependent Ginzburg-Landau equations converge to solutions of the corresponding equations with no noise.
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Omar A, Anantharamaiah KR, Rupen M, Rigby J. VLA detection of OH absorption from the elliptical galaxy NGC 1052. A&A. 2002;381(1):L29–L32.
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Kawamura J, Hunter TR, Tong CYE, Blundell R, Papa DC, Patt F, et al. Ground-based terahertz CO spectroscopy towards Orion. A&A. 2002;394(1):271–4.
Abstract: Using a superconductive hot-electron bolometer heterodyne receiver on the 10-m Heinrich Hertz Telescope on Mount Graham, Arizona, we have obtained velocity-resolved 1.037 THz CO () spectra toward several positions along the Orion Molecular Cloud (OMC-1) ridge. We confirm the general results of prior observations of high-J CO lines that show that the high temperature, , high density molecular gas, , is quite extended, found along a ~ region centered on BN/KL. However, our observations have significantly improved angular resolution, and with a beam size of we are able to spatially and kinematically discriminate the emission originating in the extended quiescent ridge from the very strong and broadened emission originating in the compact molecular outflow. The ridge emission very close to the BN/KL region appears to originate from two distinct clouds along the line of sight with and ≈ . The former component dominates the emission to the south of BN/KL and the latter to the north, with a turnover point coincident with or near BN/KL. Our evidence precludes a simple rotation of the inner ridge and lends support to a model in which there are multiple molecular clouds along the line of sight towards the Orion ridge.
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