High band gap HgCdTe optical waveguides designed for 10.6 μm

Theoretical analysis of high band gap Hg/sub 1-x/Cd/sub x/Te infrared absorption and consideration of the available metallurgical processes show the ability of this material to give rise to optical waveguides exhibiting characteristics equivalent or better than classical III V infrared waveguides at 10.6 μm. The E.D.R.I. process (Isothermal Evaporation Diffusion) has been used to grow HgCdTe layer on CdTe substrates. The Hg/sub 1-x/Cd/sub x/Te (x = 0.5) source material has been obtained by the Travelling Heater Method. Exceptionally transparent material at 10.6 μm is obtained for Cd composition x greater than 0.5. The E.D.R.I. process produces graded composition layer ranging from x = 0.55 at the surface to x = 1 in the substrate, giving rise to highly transparent graded index waveguides