STUDY ON ULTRAFAST UNIDIRECTIONAL ELECTROOPTIC DEFLECTOR AND ITS APPLICATION

点击翻译按钮获取中文摘要

The purpose of this study is development of ultrafast electrooptic modulators and deflectors which are applicable to generation and control of ultrashort optical pulses. For this purpose, we have developed the specially designed electrooptic modulators/deflectors which can operate with extremely large modulation indices in the 10 GHz region and can generate extremely wide optical sideband.Here, we, at first, continued the study on new kinds of electro-optic phase modulator as well as deflector utilizing quasi velocity matching (QVM) with periodic domain inversion of the electro-optic crystals. As a result, we have established stable method to generate the optical sidebands whose width is in the THz region. In addition, we proposed a new kind of electro-optic deflector with tilt periodic domain inversion of the electro-optic crystal, where the periodic structure is used for quasi-velocity matching between the driving electric signal and the traveling light wave as well as inducing the traveling phase grating with the pitch free from the electrical wave-length.Using this device, we can obtain the deflector and the frequency shifter which is similar to an acousto-optic deflector (AOD) but its driving frequency is much higher than AOD.We analyzed the operation of the new device theoretically and fabricated this kind of deflector with a LiTaO_3 EO crystal. In the preliminary experiment, we confirmed its operation at 16.25GHz.We also have applied the patent of this new deflector through the Japan Society for the Promotion of Science (JSPS).