Guided wave modulators in Ti ion implanted LiNbO/sub 3/ waveguides

Electrooptic modulators in Ti-ion-implanted LiNbO/sub 3/ waveguides are discussed. Low loss (<1-dB/cm) planar and channel waveguides were fabricated and compared to indiffused waveguides. Higher Delta n values are obtained, allowing smaller waveguide geometries and tighter mode confinement. Wavelengths of 0.85 and 1.3 mu m are used. The small mode profiles resulting from the Ti doses up to 4*10/sup 17/ Ti/cm/sup 2/ resulted in V-L products of 8.8 V-mm at 0.85 mu m and 20 V-mm at 1.3 mu m. These values are lower than any previously reported for a Mach-Zehnder modulator using a buffer layer. Comparison of diffused and implanted waveguide modulators indicated that modular efficiency can be optimized by electrode gap spacing and enhanced with smaller mode profiles achievable in implanted guides.<
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