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Electro‐optic (E‐O) materials are essential to modern information society, especially for optical switches, modulators, and filters in optical communication. In this paper, ultrahigh transparent (1−x)Pb(Mg1/3Nb2/3)O3‐xPbTiO3 (PMN‐PT) relaxor ferroelectric ceramics are fabricated. The effect of Sm‐doping content (0, 0.5, 1.0, 1.5, and 2.0 mol%) on PMN‐PT transparent ceramics is systematically investigated on the optical transparency, electro‐optic coefficient, extinction ratio, and half‐wave voltage. Results indicate that 0.5 mol% Sm‐doped PMN‐PT ceramic shows the optimal comprehensive performance, including high transparency of 69.6%, large quadratic E‐O coefficient of 35 × 10–16 m2 V−2, decent extinction ratio of 32 dB, and low half‐wave voltage (113 V at d = L = 1 mm). An electro‐optic modulator is designed based on the PMN‐PT transparent ceramics and its application in optical communication is realized, such as rapid information modulation, analog signal (audio frequency), and digital signal (graphic patterns) transmission. These results indicate that Sm‐doped PMN–xPT transparent ceramics are promising candidates for E‐O modulation applications.

Composition dependence of interface control, band alignment and electrical properties of HfTiON/Si grown by sputtering has been studied by spectroscopy ellipsometry (SE), x-ray photoelectron spectroscopy (XPS) and electrical measurement. Analysis from XPS has confirmed that the interfacial layer consisting of silicate and SiO x is formed unavoidably, irrespective of composition ratio. Meanwhile, reduction in band gap and asymmetric band alignment has been detected for HfTiON films with the increase in Ti composition. To meet the requirements of high-k dielectrics with the barrier height of over 1 eV, the incorporation composition ratio needs to be carefully optimized. As a result, improved C-V characteristics and reduced leakage current have been achieved from HfTiON gate dielectric MOS capacitors with optimized composition ratio of Hf:Ti = 1:1, which can be attributed to the reduction in oxygen-related traps and the obtained near-symmetric band alignment relative to Si.

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