We study the dynamics of an array of single mode semiconductor lasers globa
lly but weakly coupled by a common external feedback mirror and by-nearest
neighbor interactions. We seek to determine the conditions under which all
lasers of the array are in phase, whether in a steady, periodic, quasiperio
dic, or chaotic regime, in order to maximize the output far field intensity
. We show that the delay may be a useful control parameter to achieve in-ph
ase synchronization. For the in-phase steady state, there is a competition
between a delay-induced Hopf bifurcation leading to an in-phase periodic re
gime and a delay-independent Hopf bifurcation leading to an antiphased peri
odic regime. Both regimes are described analytically and secondary Hopf bif
urcations to quasiperiodic solutions are found. Close to the stable steady
state, the array is described by a set of Kuramoto equations for the phases
of the fields. Above the first Hopf bifurcation, these equations are gener
alized by the addition of second and third order time derivatives of the ph
ases.