Mach-zehnder Electro-optic Modulator Optical Bias

Since the emergence of integrated optics has been a very active frontier of optoelectronics fields. The various types of waveguide production based on crystal materials have the rapid development in optical communications and information processing. According to the design of integrated Mach-Zehnder interferometer, electro-optic modulators and electromagnetic field sensor devices emerged.In high-speed optical communication system, as an external modulator of signal source, Mach-Zehnder electro-optic modulators can get the narrow spectral width of modulation signal, and reduce the impact of fiber dispersion. In addition, electro-optic modulators, using Mach-Zehnder interferometer, can modulate at high speed and satisfy the requirements of the development of high speed fiber transmission systems. So high speed electro-optic modulators have been key devices for large capacity optical fiber transmission network and high speed optoelectronics signal processing system. The electro-optic modulators, using Mach-Zehnder interferometer, have bright prospects in the future.Meanwhile, the optical waveguide electric field sensors based on the same principle have the new optical structure with optical system integration. The optical waveguide electric field sensors with those unique advantages are better than other sensors in the detection field. It integrates optical system in the same substrate, miniatures the detection system. In addition, it has good stability, high precision. The optical waveguide electric field sensors have broad application prospects in the research, manufacturing, communications, aerospace and other fields. And they have good social and considerable economic benefits. Today they have become a subject of intense study.Mach-Zehnder electro-optic modulators and optical waveguide electric field sensors are made to work in the linear region by being applied dc bias. But it will disturb the properties of the devices. The subject of this thesis is to study the optical bias of the devices.First, based on the principle of electro-optic modulators, studies have been made on optical path asymmetric bias of Mach-Zehnder interferometer. Finite Difference Beam Propagation Method (FD-BPM) is introduced to simulate two dimensions Mach-Zehnder interferometer. According to the results from the analysis and simulation, compared to non-integrated optical bias, the sensitivity of optical waveguide electric field sensors is improved.Second, studies have been made on the refractive index of Mach-Zehnder interferometer. The refractive index is changed to achieve optical bias. The sensitivity of optical waveguide electric field sensors is improved. The sensitive error and the dynamic range are decreased, but better than the optical path asymmetric bias. At last, integrated Mach-Zehnder interferometer is pressed to achieve optical bias. The conductor loss and chip parameter of electro-optical modulators is increased. A set of optical system is designed for it in the final chapter. The results of experiments match with the theoretic value approximately.The detailed theory and design about three kinds of optical bias have been finished in this thesis. The results of lots simulations and experiments have showed they have important theoretic and practical meaning for electro-optic modulators.