Lateral mode discrimination and control in high-power single-mode diode lasers of the large-optical-cavity (LOC) type

The lateral waveguiding properties of high-power monomode LOC laser structures under both passive and active conditions are calculated theoretically and presented in graphs. Devices with W-shaped and positive-index-type lateral-direction passive waveguides are analyzed. It is found that the transverse confinement factor is peaked in the structure center and varies across the optical mode, that the lateral waveguide changes shape under current injection up to the lasing threshold, and that the lateral mode discrimination and control are functions of threshold mode gain. The implications for device design are considered in detail.