Mirror Reflectivity Dependence of Transverse-Modes in Semiconductor Lasers

A new device construction of GaAs semiconductor lasers for optical transverse-mode control is reported. An antireflective coating is deposited partially on the right and left outer regions of the front facet of a laser in order to confine laser oscillation to the central narrow portion of the active layer, and to obtain a single transverse-mode. The laser oscillation in the coated regions was suppressed at currents up to 1.09 times of the threshold in the case of a photoresist coating, and up to 1.20 times in the case of a ZnO coating. An optimum reflectivity distribution in the front facet for transverse-modes is discussed.