Strip-loaded waveguide using an underlay.

We describe how an ion-exchange waveguide was used as a strip-loading region for a planar polymer waveguide. The loading strip forms an underlay that is well preserved in the substrate. Some branching-channel waveguides were formed by this method, and wall losses were measured. The result shows that the wall losses decrease as a result of strip loading.

Cryogenic refractive indices and temperature coefficients of cadmium telluride from 6 microm to 22 microm.

The index of refraction and its variation with wavelength and temperature were measured for cadmium telluride made by chemical vapor deposition (CVD). The measurement at 20 K using liquid helium as coolant is reported for the first time. The refractive index at 10 microm and 20 K is 2.6466, and the average temperature coefficient at 10 microm and in the range 20-80 K is 4.9 x 10(-5)/K.

Cryogenic temperature IR refractive indices of cesium bromide and cesium iodide.

The refractive indices and their variation with temperature and wavelength in the range 80-300 K and 2-30 microm are measured for cesium bromide and cesium iodide. The indices are also fitted using both Sellmeier and Herzberger types of equations.