分数阶傅里叶变换在非平稳信号的分析和处理中具有非常重要的应用。然而，数字域实现方法存在庞大的计算开销和宽带高精度数字化瓶颈问题。目前，利用光波的宽带、高速特性在模拟域实现信号的分数阶傅里叶变换是避免上述问题的潜在技术途径。为了解决现有光学分数阶傅里叶变换器分辨率较低且阶数固定的问题，本项目提出了一种基于移频光环路实现宽范围可调谐等效大色散的方法，并利用该方法实现阶数可调谐的高精度光学分数阶傅里叶变换器。项目拟从理论分析、数值仿真和实验验证等方面，研究移频光环路的宽范围可调谐等效大色散实现机理及方法，研究基于移频光环路的光学分数阶傅里叶变换器实现机理和特性，研究可调谐高精度光学分数阶傅里叶变换器在实时信号分析和处理中的实验应用等，期望促进光学模拟信号实时处理的发展。

Fractional Fourier transform plays an important role in the application of non-stationary signal analysis and processing. Nevertheless, the implement method in digital domain spends enormous expenditure on computing, and is confronted with the bottleneck of achieving high-accuracy digitization of wideband signals. In recent years, the implementation of fractional Fourier transform in analog domain with the assistance of lightwave, which utilizes its characteristics of broadband and high speed, is regarded as a potential technique to solve the above-mentioned problems. In order to overcome the issues of low resolution and fixed order in the existing optical fractional Fourier transformers, a new method to achieve a large equivalent dispersion with a free tunable scale is proposed based on a frequency-shift optical loop in this project. Using this method, a tunable optical fractional Fourier transformer with a high resolution is realized. The research content of this project can be summarized as follows. Firstly, the realization mechanism and method of a large equivalent dispersion with a free tunable scale in a frequency-shift optical loop will be researched. Then, the realization mechanism of an optical fractional Fourier transformer based on a frequency-shift-optical loop will be researched, and its characteristics will be analyzed. Finally, the experiment application of a tunable optical fractional Fourier transform with a high resolution in real-time signal analysis and processing will be researched. The research will be carried out in full-scale, including theoretical analysis, numerical simulation and experiment verification, which is expected to promote the development of the optical real-time signal processing.