Strained Layer InGaAs GRIN-SCH Lasers Grown by MBE

The use of ternary In compounds in the active region of a diode laser allows devices to be constructed which operate at wavelengths longer than that obtainable from binary GaAs. If these In compounds are included in a structure grown on a GaAs substrate then they need to be kept thin enough (pseudomorphic) to avoid misfit dislocations which adversely affect device performance. A few lasing devices using pseudomorphic InGaAs have been reported previously (1,2) without comparison to the equivalent structure with no pseudomorphic layer. In this work two laser diode structures are compared: one containing strained InGaAs and the other identical in all respects except with unstrained GaAs in place of the strained InGaAs.