Abstract

The quantum cascade laser [ 1 ] is a new device which takes great advantage of the inherent flexibility and unique atomic-like properties of the intersubband transitions in quantum wells. After our first demonstration based on a three well active region with a diagonal transition in real space,[1] we have developed a more efficient design based on a two well active region with a vertical trnsition and a Bragg electron confinement (Fig. 1).

© 1996 Optical Society of America