TITLE:
Nonlinear Dynamics in Directly Modulated Semiconductor Lasers with Optical Loop Mirror Feedback
AUTHORS:
Hani J. Kbashi
KEYWORDS:
Nonlinear Dynamics; Nonlinear Loop Mirror; Pulse Multiplication; Optical Chaotic; And Pulse Mode Locking
JOURNAL NAME:
Optics and Photonics Journal,
Vol.2 No.4,
December
28,
2012
ABSTRACT:
The investigation of the
nonlinear dynamics of a semiconductor laser based on nonlinear optical loop mirror
(NOLM) feedback using Ge doped optical fiber was carried out experimentally. Animations
of compilations of the output power as a function of time series and phase plane
with effects of optical feedback level, carrier current and modulation signal strength
are demonstrated as a tool to give insight into the laser dynamics. Different dynamic states, including 2×, 4× multiplication and quasi-periodic and periodic frequency-locked
pulsing states extended to chaotic behaviour were observed
by varying the parameters of modulated frequency and optical feedback strength. The frequency-locked pulsing
states were observed to exhibit a harmonic frequency-locking phenomenon and the
pulsing frequency is locked to a harmonic nonlinearity in loop instead of the modulated
frequency.