Sulfuric acid proton exchanged channel waveguides fabricated in LiNbO/sub 3/

The first demonstration of proton exchanged channel waveguides formed in z-cut LiNbO/sub 3/ by exchange in sulfuric acid is presented. The single polarization guides can be produced using fabrication conditions similar to those previously reported for benzoic acid guides. The process is entirely compatible with clean room facilities and wafer level production. Guides were produced at 160 degrees C using a SiO/sub 2/ mask. Best results for lambda =1.3 mu m were achieved with a 2.25-h exchange and a 4-h anneal at 360 degrees C. The process has been successfully transferred into a class 100 clean-room facility.<
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