Modulation Bandwidth Control of Light Modulator and its Application

点击翻译按钮获取中文摘要

Periodic domain inversion of electrooptic crystals makes quasi-velocity-matching possible between light and microwave velocities in collinear microwave light modulator and provides large phase modulation index enough for generating femtosecond light pulses. In this research, we investigated the control of modulation bandwidth and band-shape by changing domain inversion pattern on the electrooptic phase modulator from simple periodic rectangles. We found some useful patterns of domain inversion that are suitable for wideband flat microwave modulation and an efficient modulator for specific two microwave frequencies by theoretical calculation. Domain inversion of electrooptic crystals was investigated for precise domain control. Charge control was quite important, so we employed current monitoring system for automatic domain control. We investigated novel domain pattern for ultrafast light control. We developed a diffractive optical modutator at a microwave frequency of which operation is similar to AOM. A guided wave modulator developed with domain inversion was suitable for ultrafast light pulse generation. All devices were optical sideband generators at microwave frequencies and the spectral control with dispersive devices makes ultrafast light pulse control possible.