Optimization and characterization of index-guided visible AlGaAs/GaAs graded barrier quantum well laser diodes

Index-guided, single and multiple stripe, visible laser diodes (
\lambda = 6950-7150
Å) have been fabricated and characterized. These structures utilize a graded barrier quantum well laser structure having high aluminum composition (
x = 0.60-0.85
) confining layers to obtain low threshold current. The use of thin AlAs quantum well barrier layers allows short wavelengths to be obtained from the quantum size effect in binary GaAs wells without the need for alloy Al
x
Ga
1-x
As wells. Index-guiding is accomplished by use of either a complementary self-aligned structure or a shallow mesa laser structure allowing stabilized single-mode laser operation.