Growth of CdGeAs/sub 2/ for mid- to far-IR frequency conversion

Summary form only given. Cadmium germanium arsenide, CdCeAs/sub 2/, has long been sought after as a promising frequency conversion material for the mid- to far-infrared based on its high nonlinear optical coefficient (236 pm/V, the highest of any known compound) and potentially wide transparency range (2.3-17 /spl mu/m) The material also has a high thermal conductivity which is desirable for high average power applications. The difficulty in achieving such crystals arises from a persistently concave solid-liquid interface shape during growth (which favors polycrystallinity) and from a 14-fold anisotropy in thermal expansion coefficient between the a and c axes (which almost inevitably causes severe cracking). We have largely overcome these difficulties using the horizontal gradient freeze growth technique.