Localized Structures in Dissipative Nonlinear Systems - Abstract
Ackemann, Thorsten
Phase, frequency and polarization state of solitons in coherently driven optical cavities are locked to the corresponding properties of the holding beam whereas they are free in cavity soliton lasers, i.e. each small solitonic microlaser within the pumped aperture has the freedom to choose polarization and frequency within the limitations of the cavity setup and its phase arises from spontaneous symmetry breaking. It is then obviously interesting to investigate how these internal degrees of freedom are affected, if two or more laser solitons are interacting.
In real systems, spatial disorder is known to play a strong role limiting the number of locations where cavity solitons can exits in a driven system. We are investigating additional consequences of disorder for laser cavity solitons and find that different laser solitons typically have different frequencies, but can frequency and phase lock depending on parameters. Synchronization of nonlinear oscillators in spite of disorder is a basic paradigm of Nonlinear Science and the long term vision is the study of a complex network of which have the freedom of choosing frequency, phase, polarization and location simultaneously.
The experimental system is based on a vertical-cavity surface-emitting laser (VCSEL) emitting at 980 nm with a diameter of 200 microns. It is coupled to a volume Bragg grating (VBG) providing narrow-band frequency-selective feedback via a self-imaging cavity. We demonstrate partial and complete locking via interference fringes in the far field and spectral measurements. Indications for hysteresis are found. First results on the modelling in class A and class B laser models are presented.
T. Ackemann 1), N. Radwell 1), P. V. Paulau 2), C. McIntyre 1), G.-L. Oppo 1), W. J. Firth 1)
1) University of Strathclyde, SUPA and Department of Physics, 107 Rottenrow East, Glasgow G4 0NG , Scotland, UK
2) IFISC (CSIC-UIB), Campus Universitat Illes Balears, E-07122 Palma de Mallorca, Spain