A heterostructure semiconductor laser with graded‐index waveguide and separate carrier and optical confinements prepared by molecular beam epitaxy is discussed. These lasers have very low broad‐area threshold current densitiesJth500 A/cm2and support narrow beams of Gaussian distribution with far‐field half‐power full‐width in the direction perpendicular to the junction plane &Vthgr;⊥∼20°–30°. It is also shown that only when the active layer thickness is ≲700 A˚ a significantly lowerJthis obtained by employing the symmetric laser structure instead of the regular double heterostructure.