Distributed-feedback coupling in Ga(1-x)Al(x)As double-heterostructure lasers: effect of aluminum concentration.
The variation of the feedback coupling coefficient in Ga(1-x)Al(x)As distributed-feedback (DFB) lasers as a function of the Al concentration surrounding the GaAs optical confinement waveguide is considered. An optimum thickness for which the feedback coupling is maximum is determined for each transverse mode. The largest such maximum occurs for the lowest order mode. Fractional Al concentrations that yield symmetrical optical waveguides are found to be most effective in minimizing threshold current density, with the maximum Al concentrations being limited by doping and lattice mismatch considerations.
J T
JT
Boyd
D B
DB
Anderson