1.3 MU-M LASERS ON GAAS(111)B EMPLOYING ORDERED (INAS)(1)(GAAS)(1) QUANTUM-WELLS FOR HIGH-FREQUENCY RESPONSE APPLICATIONS

We propose a novel laser active region design that employs a strained and ordered (InAs)(1)(GaAs)(1) quantum well on a GaAs(111)B substrate for 1.3 mu m high-speed applications. The increased Matthews-Blakeslee critical thickness for this orientation as compared to the (001) case allows for wider wells with higher indium compositions. In the In0.5G a0.5As case, however, the bandgap is noe significantly affected by the reduced quantum confinement because an increase in the hydrostatic st rain component of the Hamiltonian for the (111)-orientation approximat ely negates any narrowing effects. By using an alternate monolayer sup erlattice active region to replace the alloy, we find that wavelengths well beyond 1.3 mu m can be achieved. We also discuss some of the adv antages of moving to the (111)-orientation that indicate higher modula tion bandwidths are possible using this material system over conventio nal 1.3 mu m laser diodes on InP substrates. (C) 1997 Elsevier Science Ltd.