J. D. Cooper

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Most signal averaging processes used for cardiac signals align successive waveforms using a template matching process. In addition to achieving accurate temporal alignment of the signals, this operation must also ensure that the signal average comprises signals of the same morphology. For P wave signal averaging, systems designed for QRS complex averaging(More)
A stochastic, semiclassical model is developed for a multimode, homogeneously broadened laser with rapid di-pole dephasing, appropriate for semiconductor, Ti:sapphire, or dye lasers. The theory self-consistently incorporates population dynamics including temporal beating effects and relaxation oscillations, spatial hole burning , coherent-wave mixing, and(More)
Calculations of the longitudinal mode functions for the electric field of a compound-cavity laser show that the loss and gain coefficients are given by the Airy formula, as a function of the mode frequencies. Further, when the external cavity is longer than the gain-medium cavity, the frequency dependence of the gain is stronger than that of the loss, even(More)
The turn-on-time statistics for an individual longitudinal mode and the total intensity of a multimode laser are shown to be very different. In both experiment and theory we find that the differences are due mainly to transitory modes that decay as a result of frequency-dependent losses and gains. Associated with this phenomenon is a kink in the time(More)
The technique of dc-balanced, pulsed homodyne detection for the purpose of determining optical-field statistics on short time scales is analyzed theoretically. Such measurements provide photon-number and phase distributions associated with a repetitive signal light field in a short time window. Time-and space-varying signal and local-oscillator pulses are(More)
An experimental determination of the uncertainty product for the phase and photon number of a mode of the electromagnetic field is performed. The expectation value of the commutator that sets the lower bound for the uncertainty product is also determined experimentally. This is accomplished by using optical homodyne tomography to measure the density matrix(More)
Stable perfectly-matched-layer boundary conditions for finite-difference time-domain simulation of acoustic waves in piezoelectric crystals. Abstract Perfectly matched layer (PML) boundary conditions are derived for finite-difference time-domain analysis of acoustic waves within piezoelectric crystals. The robustness and effectiveness of the derived(More)
For lung transplantation the technique of flushing the donor pulmonary vascular bed may provide advantages in lung preservation such as rapid cooling and washout of blood. However, rapid cooling of the ischemic lung may also produce adverse effects. The aim of this study was to compare methods of cold flushing and topical cooling, and to evaluate the effect(More)