Fabrication of buried channel waveguides in fused silica using focused MeV proton beam irradiation

Low-loss channel waveguides have been fabricated in fused silica using a beam of MeV protons focused down to a spot size of several microns, ay using a combination of beam and sample scanning, single- and multimode graded index waveguides with lateral dimensions do-cvn to approximately 5 mu m x 5 mu m have been fabricated using ion doses in the range (3 x 10(14))-(6 x 10(16)) ions/cm(2). Typical beam currents in the range 100 pA-10 nA were used. Optical mode profiles have been measured at 670 nm and propagation losses of the order of 3 dB/cm measured in unannealed samples, Annealing the substrate for one h at 500 degrees C reduced these losses to below 0.5 dB/cm