This paper investigates the effect of the linewidth
enhancement factor on the operation and intensity noise
fluctuations of 980-InGaAs/InP fiber grating lasers operating
under strong optical feedback. The analyses are performed in
terms of the temporal trajectory of the laser intensity, bifurcation
diagram and relative intensity noise. The influence of intrinsic
fluctuations in the intensity and optical phase of the lasing field on
the laser dynamics were taken into account. The laser diode
operates in pulsation under strong optical feedback and at small
and relatively large values the linewidth enhancement factor. The
optical feedback noise is found to be as low as the quantum noise
level when the laser is operated in pulsing region and at relatively
large values of the linewidth enhancement factor