D. Zheng et al., DIFFUSION BONDING OF GAAS WAFERS FOR NONLINEAR OPTICS APPLICATIONS, Journal of the Electrochemical Society, 144(4), 1997, pp. 1439-1441
Diffusion-bonded stacked periodic structures represent a new family of
optical materials with spatially patterned nonlinear properties. The
bonding process preserves both the optical and mechanical properties o
f the bulk materials. GaAs devices up to 20 layers were diffusion bond
ed and characterized. Optical loss was from interfacial voids and gaps
at shorter wavelengths and from processing-induced p-type free carrie
r absorption at longer wavelengths.