Dresden 2003 – wissenschaftliches Programm

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DF: Dielektrische Festkörper

DF 2: Elektrische und optische Eigenschaften II

DF 2.8: Vortrag

Montag, 24. März 2003, 17:10–17:30, HSZ/403

Application of Small Signal Amplification in a Series Resonance Circuit with TGS-Capacitor as Pyroelectric Detector — •Martin Diestelhorst and Ralf-Peter Kapsch — Martin-Luther-Universität Halle-Wittenberg, Fachbereich Physik, Friedemann-Bach-Platz 6, 06108 Halle

The strong dielectric nonlinearities of ferroelectric TGS during switching are used to cause different kinds of bifurcations up to chaotic behaviour in a series resonance circuit. These effects may be observed, if the external parameters of the resonance circuit like amplitude and frequency of the driving voltage or temperature of the ferroelectric capacitor are suitably chosen. They are well understood from the view-point of nonlinear dynamics. By means of this theory it was predicted, that each nonlinear dynamical system in the vicinity of a bifurcation can act to amplify small periodic perturbations. In a first step this amplification could be verified in the nonlinear series resonance circuit for the period-doubling bifurcation by introducing the periodic perturbation into the system as an amplitude modulation of the driving voltage. Here we report about the amplification of perturbations, which are introduced into the circuit via pyroelectric effect. Detailed investigations were performed to optimize this effect. The result may be considered as a new method of pyroelectric detection.