A new LiTaO3 electro-optic polarization modulator utilizing traveling-wave electrodes and a double periodic poling structure is proposed. Utilizing the double periodic poling structure, both quasi-phase matching between TE and TM guided-modes, and quasi-velocity matching between a lightwave and a modulation microwave are obtainable at modulation frequencies over 10 GHz.

A novel structure of a resonator type guided-wave electro-optic intensity modulator is introduced that uses a higher-order harmonic resonant electrode of coupled microstrip lines combined with polarization-reversed structure. The light modulation cancellation caused by the light transit-time effect in the resonant electrode, which is longer than the wavelength of the standing wave, is compensated for to enhance modulation efficiency. The modulator for 26 GHz operation was designed and fabricated with a LiTaO3 substrate. The modulation electrode is 9.03 mm long for seventh order harmonic resonance by RF signal. The workability of the modulator was confirmed by experiments with 1.3 µm wavelength light.

We propose and experimentally confirm two approaches to improve the sensitivity of the H-type piezoelectric crystal gyroscope of LiTaO3. One is to adjust the resonant frequencies of the fz mode through additional mass control; the other is to change the driving mode from fx mode to fz mode, while the driving frequency is the resonant frequency of the fx mode. The sensitivity of the unit driving voltage is almost the same, but the threshold driving voltage level may increase more than 1,000 times, because it is far from the mechanical resonance. The high sensitivity of 0.11 pC (deg/sec) was obtained at a driving voltage of 30 Vpp.