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Biomedical subjects

K A Shore

Publications and source records attributed to K A Shore.

8 recordsLinked to original sources
PubMed2006

Correlation dimension signature of wideband chaos synchronization of semiconductor lasers.

Chaos data analysis has been performed on the chaotic output power time series data from a synchronized transmitter-receiver pair of semiconductor lasers. The system uses an asymmetric, bidirectional coupling configuration between the master (transmitter), which is a laser diode with optical feedback, and a stand-alone slave semiconductor laser. The correlation dimension of the chaotic time series has a minimum value of 4, which was obtained from high-bandwidth measurements. The correlation dimensions for both the master and the synchronized slave are identical when the cross-correlation coefficient of the synchronized chaos is above 0.9. These results establish correlation dimension analysis as an effective tool for the determination of the quality of wideband chaos synchronization.

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PubMed2005

Generalized synchronization in time-delayed systems.

We investigate the generalized synchronization between two unidirectionally linearly and nonlinearly coupled chaotic nonidentical Ikeda models and find existence conditions of the generalized synchronization. Also we study the chaos synchronization between nonidentical Ikeda models with variable feedback-delay times and find the existence and sufficient stability conditions for the retarded synchronization manifold with the coupling-delay lag time. Generalization of the approach to the wide class of nonlinear chaotic systems is also presented.

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PubMed2003

Nullified time-of-flight lead-lag in synchronization of chaotic external-cavity laser diodes.

Synchronization of three chaotic diode lasers is effected in a transmitter-mediator-receiver configuration. The transmitter laser's output is bidirectionally coupled to the mediator laser to achieve anticipating synchronization in their output intensities. The mediator laser's output is unidirectionally coupled to the receiver laser to achieve lag synchronization in their output intensities. This combination of lead and lag synchronization nullifies the time-of-flight lead-lag in synchronization between the transmitter and receiver lasers. This approach provides a means of eliminating time-of-flight delays in the synchronization of remote transmitters and receivers.

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PubMed2002

Lag times and parameter mismatches in synchronization of unidirectionally coupled chaotic external cavity semiconductor lasers.

We report an analysis of synchronization between two unidirectionally coupled chaotic external cavity master and slave semiconductor lasers with two characteristic delay times, where the delay time in the coupling is different from the delay time in the coupled systems themselves. We demonstrate that parameter mismatches in photon decay rates for the master and slave lasers can explain the experimental observation that the lag time is equal to the coupling delay time.

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PubMed2002

Inverse anticipating chaos synchronization.

We derive conditions for achieving inverse anticipating synchronization where a driven time-delay chaotic system synchronizes to the inverse future state of the driver. The significance of inverse anticipating chaos in delineating synchronization regimes in time-delay systems is elucidated. The concept is extended to cascaded time-delay systems.

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PubMed2001

Experimental demonstration of anticipating synchronization in chaotic semiconductor lasers with optical feedback.

We report the first experimental observation of anticipating chaotic synchronization in an optical system using two diode lasers as transmitter and receiver. The transmitter laser is rendered chaotic by application of an optical feedback in an external-cavity configuration. It is found that the anticipation time does not depend on the external-cavity round trip time of the transmitter.

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PubMed2000

Wavelet operators for nonlinear optical pulse propagation.

A method that uses discrete wavelet transforms for the solution of evolution equations that describe optical pulse propagation in nonlinear media is presented. The theory of orthogonal wavelet transforms is outlined and applied to the representation of optical pulses. Wavelet transform representations of propagation operators are presented and applied to the nonlinear Schrödinger equation, yielding results that are indistinguishable from traditional Fourier-based simulations. The compression properties of wavelet representations of optical pulses permit significant improvement in execution speed compared with that of the split-step Fourier method.

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