Patent ID: 8000367
Filing Date: 2011-08-16
Classification: B82Y,H01S

Abstract:
1. A unipolar quantum cascade laser with several semiconductor multilayer structures that are layered behind one another between two electrodes in a periodic sequence such that a multilayer structure designed for light emission and a multilayer structure designed for electron transport respectively alternate, wherein the multilayer structures designed for light emission respectively feature at least one upper and one lower energy level for electrons, between which electron transitions emitting light take place, and the multilayer structures designed for electron transport respectively allow the electron transport from the lower energy level of the preceding multilayer structure designed for light emission referred to the transport direction into the upper energy level of the following multilayer structure designed for light emission referred to the transport direction, and wherein the multilayer structures designed for light emission comprise at least one quaternary material layer as barrier layer, characterized in that the multilayer structures designed for light emission are realized in such a way that a highest local maximum of the square of the quantum-mechanical wave function for the electrons in the upper energy level occurs in a first quantum well that lies closest to the preceding multilayer structure designed for electron transport referred to the transport direction, in that a second highest local maximum of the square of the quantum-mechanical wave function of the electrons in the upper energy level lies in a second quantum well situated adjacent to the first quantum well referred to the transport direction, and in that the highest and the second highest local maximum of the square of the quantum-mechanical wave function for the electrons in the upper energy level differ by less than 50%.