| With the development of the optoelectronic technique, the mixing and interconversionbetween photonics technology and microwave technology have become increasingly closely.With the outstanding characteristics such as high stability, low cost, simple structure andimmunity to electromagnetic interference, the photonic high frequency microwave signalgeneration has become the research topic of microwave photonics. Meanwhile, researchershave started plenty of research about microwave phase shift based on photonic techniqueduring the past few years. As the optical fiber communication are moving toward thedirection of ultra-high speed, ultra-large capacity and ultra-long haul (3U), Photonicgeneration of frequency-quadrupled microwave signal with tunable phase shift will play animportant role in the radio over fiber system. The main contents of the dissertation are as thefollowing:(1) The operation principle of the balanced structure of the Mach-Zehnder Modulator(MZM) is analyzed. In order to lay the foundation for the theoretical analysis of opticalfrequency-quadrupled microwave signal generation, formulae are derivated for the sidebandsgeneration based on MZM. Further more, the principle of the microwave signal generationbased on external modulation has been theoretically explained.(2) The effects caused by imbalanced MZM structure to sideband modulation is studied.After simulation, we find out the relationship between the change of the physical parameterof MZM and the sideband modulation performance. The working principle of theimbalanced MZM is analyzed to give theoretical explanation to the simulation results.(3) A photonic scheme for microwave frequency quadrupling with arbitrary tunablephase shift is proposed and experimentally demonstrated. The system performance of phaseshift and microwave signal generation are evaluated respectively. Using preliminaryexperiment results, we illustrate the system has the ability to support multi-wavelengthoperation. |
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