UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS

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2022-07-01 17:27

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Conference: Bucharest University Faculty of Physics 2019 Meeting


Section: Optics, Spectroscopy, Plasma and Lasers


Title:
Chaotic, tunable high frequencies oscillations induced in a double-reflector external cavity semiconductor laser


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


*
Affiliation:
(1) University "Politehnica" of Bucharest, Academic Center for Optical Engineering and Photonics, Faculty of Applied Sciences, Physics Department, Bucharest, Romania

(2) National Institute for Laser, Plasma and Radiation Physics, Magurele, Romania

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


E-mail
ionut.andrei@inflpr.ro


Keywords:
semiconductor laser, chaotic dynamics, double reflector external cavity, external cavity oscillations, tunable frequency


Abstract:
In this paper we show experimentally that one may generate chaotic oscillations with tunable high frequencies (υHFO) in the emission of a semiconductor laser (SL) working in external optical feedback conditions provided by two reflectors. We use a double-reflector External Cavity SL (D-ECSL) system combining a linear external cavity (C1) limited by a diffraction grating, and a Littman cavity (C2) limited by a mirror. The grating provides feedback on first diffraction order, and the mirror on 0th – diffraction order of the grating. The optical path in C2 is longer than C1 with about 1/3 from this one. By changing the feedback intensity of C2, high frequency oscillations with tunable frequencies are obtained. The chaotic oscillations show function of C2 cavity feedback intensity, frequency values bounded by those of the short cavity (υEC1) and the first harmonic of the long cavity (υHFO-C2). Also, the values range of oscillation frequencies increase when C1 feedback intensity increases. Since these frequencies do not match to those of C1 or C2 separate cavities, they do not carry information about the geometry of the D-ECSL system. The reported results have potential of application in data encoding and information transmission using optical chaotic carriers.


References:

1. A. Bakry, S. Abdulrhmann, M. Ahmed, Theoretical modeling of the dynamics of a semiconductor laser subject to double-reflector optical feedback, Journal of Experimental and Theoretical Physics, 122, 960–969 (2016).

2. C. Onea, P.E. Sterian, I. R. Andrei, M. L. Pascu, High frequency chaotic dynamics in a semiconductor laser with double-reflector selective cavity, submitted to U.P.B. Sci. Bull., Series C (2019).



Acknowledgement:
The present research was supported by Ministry of Research and Innovation, NUCLEU program 16N/08.02.2019; Doctoral School SD ETTI-B University POLITEHNICA of Bucharest.