TUNABLE (AL)GAAS LASERS USING IMPURITY-FREE PARTIAL INTERDIFFUSION

Impurity-free interdiffusion has been used to fabricate single mode quantum well ridge lasers from the same (Al)GaAs epitaxial material which differ in emission wavelength by as much as 11.7 nm. This represents a shift of approximately 80 laser linewidths, as measured under pulsed conditions. Threshold currents for the interdiffused and nondiffused lasers are nearly identical. However, the differential quantum efficiencies of the most interdiffused lasers are a factor of 2 lower than nondiffused lasers. The interdiffusion coefficients for the quantum well laser structure are approximately a factor of 6 smaller than those observed for intrinsic GaAs multiple quantum wells.