Wide bandwidth AlAs/AlGaAs tandem Bragg reflectors grown by organometallic vapor phase epitaxy

Wide bandwidth AlAs/Al0.6Ga0.4As tandem Bragg reflectors were grown by organometallic vapor phase epitaxy. Quarter-wave reflector stacks designed for different wavelengths were placed in cascade in epitaxially grown structures to expand the high reflectance bands. Intermediate low-index layers were put in between every two stacks to suppress the transmission peaks in the centers of the combined high reflectance bands. While a single-stack structure showed a full width half-maximum bandwidth of 500 Angstrom, the two-stack and the three-stack structures effectively doubled and tripled this bandwidth to approximately 1000 and 1500 Angstrom, respectively. (C) 1995 American Institute of Physics.