H01S 5/222

Structure or shape of the semiconductor body to guide the optical wave {; Confining structures perpendicular to the optical axis, e.g. index or gain guiding, stripe geometry, broad area lasers, gain tailoring, transverse or lateral reflectors, special cladding structures, MQW barrier reflection layers} having a ridge or stripe structure {comprising special burying or current confinement layers having special optical properties having a refractive index lower than that of the cladding layers or outer guiding layers}