Abstract

Graded index separate confinement heterostructure single quantum well (GRINSCH-SQW ) lasers have been shown to offer a number of significant advantages over conventional double heterostructure lasers for high power applications.^1,2 The low loss of the passive waveguide regions leads to very high external differential quantum efficiencies (η_d). This coupled with the high modal gain inherent in these structures results in low threshold current densities (J_th). Moreover, the characteristic temperature (T_o) of threshold current (I_th) tends to increase with cavity length while the threshold current itself increases only slowly, making junction-side up operation to high CW powers possible under a wide range of conditions.^3,4 This paper explores the benefits of six GRINSCH-SQW variations and reports the optimized structure from this survey as measured from over 400 devices tested in recent months.

© 1987 Optical Society of America