Faculty of Physics - University of Bucharest

UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS

Guest
2024-11-24 22:11

HOME CONFERENCES SEARCH LOGIN NEW USER IMAGES

Conference: Bucharest University Faculty of Physics 2018 Meeting

Section: Optics, Spectroscopy, Plasma and Lasers

Title:

Experimental control of low-frequency fluctuations by current modulation in a laser diode chaotic coupled system

Authors:

Ionut-Relu ANDREI(1), Cristina ONEA(2), Paul E. STERIAN(2), Mihail-Lucian PASCU(1,3)

Affiliation:

1) National Institute for Lasers, Plasma, and Radiation Physics, Magurele, Romania

2) University "Politehnica" of Bucharest, Academic Center for Optical Engineering and Photonics, Faculty of Applied Sciences, Physics Department, Bucharest, Romania

3) University of Bucharest, Faculty of Physics, Magurele, Romania

E-mail

ionut.andrei@inflpr.ro

Keywords:

semiconductor lasers, low-frequency fluctuations, chaotic system

Abstract:

In the present work, two semiconductor lasers (SL) were optically coupled into a master - slave synchronization scheme. Both systems, master and slave, were formed by a SL operated under external optical feedback conditions in low-frequency fluctuation (LFFs) chaotic regime. The injection current of the master system is modulated at several MHz, different from the natural oscillation LFF frequency of the master which is 10 MHz, and slave which is 3.4 MHz. The rates of power dropouts in the master system and the master-slave coupled system of laser emissions were correlated with the amplitude and frequency of the modulating signal. Driving the master laser at 8 and 15 MHz induces dropouts with a periodicity of 0.125 and 0.067μs, respectively, resulting in LFFs with two dominant frequencies, the driven and the natural ones. In the coupled system, the statistical analysis of driven power dropouts shows that the rate of dropouts becomes the same for master and slave, and it corresponds to the driven frequency, when the master laser is driven at 8 MHz, and differ from this when the laser is driven at 15 MHz. The results show that the modulation at frequencies that are not in the frequency domain bounded by the natural oscillation LFF frequencies in the two chaotic systems, have no control effect on the chaotic dynamics of the coupled system. It only has the role to group the temporal periods, but at values other than the modulation one. The results allow to better understand the mechanisms that contribute to the synchronization regimes stability and chaotic dynamics control of the coupled systems.

Acknowledgement:

Acknowledgements This work was supported by Ministry of Research and Innovation (CNCS/CCCDI-UEFISCDI PN-III-P2-2.1-PED-2016-0420, PN-III-P2-2.1-PED-2016-0446), NUCLEU Program (PN 1813/2018).