Barrier Optical Waveguide Formation in La3Ga5SiO14 Crystals by High Energy Carbon Ion Implantation

The barrier planar waveguides are fabricated for the first time in z-cut LGS (La3GasSiO14) crystals by 3.0 MeV and 6.0 MeV carbon ion implantations with dose of 2×10^15 ions/cm^2 at room temperature. Four and six dark modes were observed by the prism-coupling method, respectively. The refractive index profiles were reconstructed by using the reflectivity calculation method. There are about 1.6% and 0.9% decreases at the optical barriers in the 3.0MeV and 6.0MeV cases, and the positions of the optical barriers are close to that of the damage peaks caculated by the TRIM'98 (Transport of Ions in Matter) code. It is found that the refractive index change may partly be due to the damage induced by the nuclear collision.