Biomedical subjects

AR Champneys

Publications and source records attributed to AR Champneys.

3 recordsLinked to original sources

PubMed2000

Frequency selection by soliton excitation in nondegenerate intracavity down-conversion

We show that soliton excitation in intracavity down-conversion naturally selects a strictly defined frequency difference between the signal and idler fields. In particular, this phenomenon implies that if the signal has smaller losses than the idler then its frequency is pulled away from the cavity resonance and the idler frequency is pulled towards the resonance and vice versa. The frequency selection is shown to be closely linked with the relative energy balance between the idler and signal fields.

Journal Article↗

PubMed2000

Embedded solitons in a three-wave system

We report a rich spectrum of isolated solitons residing inside (embedded into) the continuous radiation spectrum in a simple model of three-wave spatial interaction in a second-harmonic-generating planar optical waveguide equipped with a quasi-one-dimensional Bragg grating. An infinite sequence of fundamental embedded solitons is found, each one differing by the number of internal oscillations. Branches of these zero-walkoff spatial solitons give rise, through bifurcations, to several secondary branches of walking solitons. The structure of the bifurcating branches suggests a multistable configuration of spatial optical solitons, which may find straightforward applications for all-optical switching.

Journal Article↗

PubMed2000

Higher-order nonlinear modes and bifurcation phenomena due to degenerate parametric four-wave mixing

We demonstrate that weak parametric interaction of a fundamental beam with its third harmonic field in Kerr media gives rise to a rich variety of families of nonfundamental (multihumped) solitary waves. Making a comprehensive comparison between bifurcation phenomena for these families in bulk media and planar waveguides, we discover two types of soliton bifurcations and other interesting findings. The latter includes (i) multihumped solitary waves without even or odd symmetry and (ii) multihumped solitary waves with large separation between their humps which, however, may not be viewed as bound states of several distinct one-humped solitons.

Journal Article↗