Abstract
The reduction of the threshold current using quantum well (QW) structures is reviewed both theoretically and experimentally. A theory which takes into account gain flattening due to the two-dimensionality of quantum well is used to analyze experimental results of QW laser structures with various number of quantum wells. The lowesthreshold current density is realized by using single and multi quantum wells at long and short cavity lengths. An optimum cavity length, which minimizes the threshold current, is inversely proportional to thenumber of quantum wells. Close comparison between theory and experiment are made and the theory is found to be useful in optimizing quantum well structures.
