Authors
Abstract
In this paper the study of Frequency Modulation Harmonic Mode-locking for
Ytterbium Doped Fiber Laser is presented. The model studied, uses ytterbium-doped,
single mode fiber pumped by 976 nm laser source is used with 150 mW pumping
power to produce 1055 nm output laser and Frequency Modulation Harmonically
Mode-Locked by MZI optical modulator. The effect of both normal and anomalous
dispersion regimes on output pulses is investigated. Also, modulation frequency effect
on pulse parameters is investigated by driving the modulator into different frequencies
values.
This study shows the stability of working in anomalous dispersion regime and the
pulse compression effect is better than counterpart normal regime, due to the
combination effect
of both negative(Group velocity dispersion), GVD and nonlinearity. Also it shows the
great effect of modulation frequency on pulse parameters and stability of the system.
Model-locking fiber laser master equation is introduced, and using the assumed pulse
shapes for both dispersion regimes after modifying (Ginzburg-Landau equation), GLE
and by applying the moment method, a set of five ordinary differential equations are
introduced describing pulse parameters evolution during each roundtrip.To solve these
equations numerically using fourth- fifth order, Runge-Kutta method is performed
through MatLab 7.0 program.
Keywords
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