Crystalline thin-film optical waveguides of gadolinium gallium garnet
(Gd3Ga5O12) have been deposited onto heated yttrium aluminium garnet (
Y3Al5O12) substrates by a pulsed laser deposition technique. The refra
ctive indices of the films have been inferred from dark-mode prism cou
pling measurements and are in excellent agreement with the bulk crysta
l.