本文採用Z-Cut 鈮酸鋰以鈦擴散製作波導，並以馬氏調制器的形式來製作電磁場感測器，當入射雷射波長1550nm，輸入功率為10mW，其半波電壓為10V，切換消光比為23.8dB。將一微型天線直接製作於調制器上，使整個元件於100MHz與2GHz分別有最小電場感度2.85×10-3V/m及8.91×10-4V/m，並調整馬氏調制器與微型天線間的阻抗匹配，經由天線因子量測得知，操作頻寬可由100MHz到1.8GHz，包含了大部份通訊上所適用的頻段，且於2GHz有一共振響應。

The amplitude modulator of an electromagnetic field sensor using Ti diffusion process on Z-cut LiNbO3 and optical fiber link is improved by a Mach-Zehnder interferometer, whose Vπ is about 10V at 1550nm wavelength and the on-off extinction ratio is 23.8dB. In this thesis, the plane antenna was directly applied to suppress the volume and strengthen the connection between each part of the device for the purpose of optoelectronic intergraded circuit. After being ground and polished well, the device was coupled with fiber directly. Then the characteristic of the fabricated sensor were analyzed. It was found that the resulting frequency response is almost flat from 100MHz to 1.8GHz, and the resonant frequency is at 2GHz. The minimum detectable electric field strengths are 2.85×10-3V/m at 100MHz and 8.91×10-4V/m at 2GHz. Therefore, the optical electric field sensor made by LiNbO3 could become more valuable in application.

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