EXPERIMENTAL CHARACTERIZATION OF REACTIVE ION ETCHED GERMANIUM DIFFRACTION GRATINGS AT 10.6 MU-M

An experimental study of diffraction gratings reactive ion etched in g ermanium is performed. Gratings are designed for the 10.6 mu m infrare d CO2 laser. Different etchants have been compared to pattern 3-mu m-d eep grooves in the germanium layers evaporated on a GaAs substrate. Th e experimental diffraction efficiency (maximum 30%) of the prototype g ratings are in good accordance with the theoretical predictions, The U -shaped grooves have still to be further optimized. (C) 1996 American Institute of Physics.