(Al,Ga)Sb long-wavelength distributed Bragg reflectors

The authors have grown long-wavelength distributed Bragg reflectors (DBRs), using alternating layers of the semiconductors AlSb and (Al,Ga)Sb, and measured their properties. The large refractive index ratio available with these materials allows for high-reflectivity mirrors with relative few mirror pairs. A simple 10-period AlSb/GaSb DBR had a maximum reflectivity of over 98% at a wavelength of 1.92 mu m, and a 12-period Al/sub 0.2/Ga/sub 0.8/Sb/AlSb DBR exhibited reflectance greater than 99% at 1.38 mu m. These structures are easily grown by molecular beam epitaxy (MBE) and are suitable for use in surface-normal photonic devices operating at long wavelengths.<
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