Y. Champagne et al., NUMERICAL PROCEDURE FOR THE LATERAL-MODE ANALYSIS OF BROAD-AREA SEMICONDUCTOR-LASERS WITH AN EXTERNAL-CAVITY, IEEE journal of quantum electronics, 31(5), 1995, pp. 795-810
A numerical procedure for the investigation of the lateral modes of se
miconductor lasers with an external cavity is described. The propagati
on of the optical field inside the semiconductor laser is carried out
via a standard beam-propagation scheme, while the method of coordinate
scaling with the generalized Huygens-Fresnel integral allows for a co
mputationally efficient propagation of the field in the external cavit
y, Using an eigenfunction solver based on the Prony method, it is show
n that a simple external-cavity configuration comprising a broad-area
laser, a collimation lens, and a uniform end reflector can exhibit a c
omplex modal behavior, Compared to a solitary broad-area laser, optimi
zed external cavities can yield enhanced modal discriminations, result
ing in a single-lateral-mode operation with output power in excess of
100 mW along with a clean, single-lobed far-field pattern, The spatial
-filtering action of the broad-area laser is highlighted, and we also
discuss of the role played by the wavefront curvature of the beam inci
dent upon the broad-area laser for achieving an efficient suppression
of the higher order modes along with minimum increase of the threshold
current.