Abstract: A light emitting device includes an n-type AlGaN structure, a p-type AlGaN structure, and a light-emitting active-region sandwiched between the n-type AlGaN structure and the p-type AlGaN structure. A first p-contact is formed on the p-type AlGaN structure defining a light-emitting structure, a second p-contact is formed on the p-type AlGaN structure defining a light-detecting structure, and an n-contact is formed on the n-type AlGaN structure serving as a common cathode for the light-emitting structure and the light-detecting structure. There is a bridge zone between the first and the second p-contacts and the p-type AlGaN structure in the bridge zone is not removed.

Abstract: A light emitting device includes an n-type AlGaN structure, a p-type AlGaN structure, and a light-emitting active-region sandwiched between the n-type AlGaN structure and the p-type AlGaN structure. A first p-contact is formed on the p-type AlGaN structure defining a light-emitting structure, a second p-contact is formed on the p-type AlGaN structure defining a light-detecting structure, and an n-contact is formed on the n-type AlGaN structure serving as a common cathode for the light-emitting structure and the light-detecting structure. There is a bridge zone between the first and the second p-contacts and the p-type AlGaN structure in the bridge zone is not removed.

Abstract: A light-emitting device includes an n-semiconductor structure, a p-semiconductor structure and a light-emitting active-region sandwiched therebetween. An n-trough is formed to expose the n-semiconductor structure by removing a first portion of the p-semiconductor structure and the light-emitting active-region. The n-trough surrounds a p-mesa which contains a second portion of the n-semiconductor structure, the p-semiconductor structure and the light-emitting active-region. The n-trough and the p-mesa are path-connected spaces and are formed via lithography and etching using a lithographic mask which is topologically constructed via merging a unit cell's at least two transformations selected from the unit cell's translation, rotation, and reflection transformations.