Analytic technique for active mode-locked fiber lasers

Abstract EN

In this work, Amplitude modulation mode-locked fiber laser is studied, by using Ytterbium Doped Fiber Laser, single mode fiber, operating with 1055 nm wavelength with 976 nm optical pump and AM Mode-Locked by optical modulators.

A grating pair is used to compensate the normal dispersion.

The effect of both normal and anomalous dispersion regimes on output pulses are investigated.

Master equation of the Mode locking fiber laser is introduced .Pulse shapes for both dispersion regimes are assumed after modifying (Ginzburg-Landu equation) GLE which is essentially Generalized Nonlinear Schrödinger equation GNLSE and by applying the moment method, a set of five rate equations for pulse energy , pulse width, frequency shift, temporally shift and chirp, which solutions described the pulse from round trip to the next and how they approach to steady state values.

To solve these equations numerically fourth order, Runge-Kutta method is performed through Mat-Lab 7.0 computer program.

Result shows that, the output pulse width from the AM mode-Locked equals to Ʈ = 0.8ps in anomalous and Ʈ =1ps in normal regimes.

The study shows the stability of working in anomalous dispersion regime is better than normal regime.