Fundamental lateral-mode operation in broad-area lasers having built-in lenslike refractive index distributions

High power fundamental lateral-mode operation is achieved in an (AlGa)As broad-area laser diode. This diode has built-in lens-like refractive index distributions in the stripe. These distributions effectively suppress higher order lateral-mode generation by expanding the laser beam in the direction parallel to the junction. As a result, fundamental lateral-mode operation of up to 80 mW for CW operation is attained with this laser.