@InProceedings{Supelec474,
author = {Krassimir Panajotov and Mikel Arizaleta Arteaga and Miguel Valencia and Marc Sciamanna and Manuel Lopez-Amo and Hugo Thienpont},
title = {{Double cavity feedback and experimental observation of coherence resonance}},
year = {2008},
booktitle = {{Proceedings of 10th International Conference onTransparent Optical Networks (ICTON 2008)}},
volume = {2},
pages = {135},
month = {jun},
address = {Athens (Grèce)},
url = {http://dx.doi.org/10.1109/ICTON.2008.4598612},
doi = {10.1109/ICTON.2008.4598612},
abstract = {We first discuss the effect of isotropic optical feedback from an
extremely short external cavity (ESEC) (K. Petermann, 1195, K.
Hsu, et al., 1998) on the emission properties of vertical-cavity
surface-emitting lasers (VCSELs). When changing the external
cavity length a modulation of the total power and the wavelength
emitted by the VCSEL is observed with a period of half the
emission wavelength (K. Panajotov et al., 2004). By making use of
a two modes rate equation VCSEL model we develop a map of
bistability to investigate the parametric dependence of
polarization properties of VCSELs in such configuration, finding
out a periodic dependence of the polarization switching currents
on the ESEC length (K. pajanotov, et al., 2004 and M. A. Arteaga
et al., 2006). By increasing the external mirror reflectivity we
can make this periodic dependence stronger and strongly
asymmetric providing the possibility to prevent PS for any
injection current and thus, achieving polarization stabilization
in VCSELs (M. A. Arteaga et al., 2006). Further numerical
simulations with isotropic and non isotropic feedback show how
parameters as gain compression coefficients, frequency splitting
between the linearly polarized modes, differential gain and the
mirror reflectivity, affect the map of bistability (M. A. Arteaga
et al., 2006). The theoretical results are supported by extensive
experimental mapping (M. A. Arteaga et al., 2006). The switching
currents and the hysteresis width can be widely tuned by varying
the external cavity length. The amplitude of modulation of the
polarization switching current with the external cavity length is
experimentally confirmed to be proportional to the external
mirror reflectivity, proving its key role in achieving
polarization control of such lasers using optical feedback.
Moreover, by a proper choice of the optical feedback parameters,
the emission can be stabilized in any of the two linearly
polarized modes (M. A. Arteaga et al., 2006). Finally, by maki- -
ng use of the fine-polarization tuning provided by the ESEC
feedback we report on the experimental observation of coherence
resonance in a bistable system with delay (M. A. Arteaga et al.,
2006). Our system consists of a VCSEL subject to time-delayed
optical feedback simultaneously from a long and from extremely
short external cavity. Coherence resonance is experimentally
proven by analysis of the residence time distribution of the
polarization mode-hopping regime and of the signal to noise ratio
in the power spectrum.}
}