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Pattern formation in presence of walk-off for a Type-II optical parametric oscillator
No full textWe show the relevance of walk-off effects in pattern formation in a type II optical parametric oscillator at frequency degeneracy. With walk-off neglected only phase patterns are formed, and the intensity distribution is homogeneous. Walk-off changes the instability from absolute to convective for some parameter range. In the absolutely unstable regime it induces for each polarization component of light a competition between two phase stripe patterns (traveling waves) of different wavelength. Phase stripe patterns at each of the wavelengths are equally likely to be selected, and, after a transient regime of coexistence, one of them takes over. In the convectively unstable regime the existence of intensity patterns sustained by noise is shown. The patterns arise from the interference between traveling waves that are generated by the dynamical amplification of noise
Dynamics and stabilization of vectorial vortices in type-II optical parametric oscillators
No full textSynchronization of vectorial noise-sustained structures
No full textThe synchronization of vectorial, noise-sustained structures in nonlinear optical systems is discussed. In particular, the analysis is made for nondegenerate optical parametric oscillators with walk off. The interplay between walk off and noise fluctuations leads to the formation of noise-sustained transverse patterns in both the signal and idler fields. Despite the fact that both patterns are stochastic macroscopic structures driven by independent sources of noise, their correlation grows with time, finally leading to a spatially distributed time synchronization of noise-sustained structures. A physical explanation of this phenomenon is found by analyzing the linear instability process and the existence of exact nonlinear solutions that show the same correlation
Pattern Formation in a Type-II Optical Parametric Oscillator
No full textWe show the relevance of walk o e ects in pattern formation in a type II optical
parametric oscillator at frequency degeneracy Neglecting walk o only phase pat
terns are formed and the intensity distribution is homogeneous Walk o changes the
instability from absolute to convective for some parameter range In the absolutely
unstable regime it induces for each polarization component of light a competition
between two phase stripe patterns traveling waves with di erent wavelength Phase
stripe patterns at each of the wavelengths are equally likely to be selected and after a
transient regime of coexistence one of them takes over In the convectively unstable
regime we show the existence of intensity patterns sustained by noise The patterns
arise form the interference between traveling waves which are excited by noise and
dynamically ampli edThis work is supported by the European Commission through the Project QSTRUCT
ERB FMRX CT
Financial support from DGESIC
Spain Projects PB
and PB
C is also acknowledgedPeer reviewe
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