Research On Optical Information Processing Technology Based On Annular Optical Waveguide

As the competition for wireless channels in all walks of life becomes more and more fierce,the resources of the radio frequency spectrum are becoming less and less.The available spectrum covers almost all bands from 2MHz to 300GHz,and the operating frequency can only be explored in the higher spectrum range.As the operating frequency becomes higher and higher,the traditional methods of frequency measurement based on electronic devices are faced with great challenges.Therefore,the microwave frequency measurement technology based on photon-assisted emerged at this time.This technology has made up for the shortcomings of traditional electronic technology with limited instantaneous bandwidth,which has become a hot spot.Optical frequency comb is named for its comb-like shape in the frequency domain which is the most accurate frequency measurement tool so far.When measuring the frequency of broad Band microwave signal,the multi-carrier light source is required to beat with the microwave signal to achieve the function of dividing the spectrum.The most commonly used multi-carrier light source is optical frequency comb,so the quality of optical frequency comb determines the performance of the entire frequency measurement system.Among the methods of generating optical frequency comb,the cyclic frequency shift method based on optical fiber loop is preferred by researchers at home and abroad because of its flexibility.However,with the improvement of the degree of integration of optical devices,the optical micro-ring resonator has attracted more and more attention from researchers due to the disadvantages of the traditional loop cavity,such as complex construction,large volume,large time delay and limited dispersion.For these two kinds of ring structures,the main completed working is following:1.The system of frequency shift feedback ring laser is constructed.The system adopts acoustooptic frequency shifter as a circulating frequency shifter and a loop cavity to jointly form a feedback mechanism.Firstly,based on this structure,by optimizing the noise of the erbium-doped fiber amplifier and the length of the erbium-doped fiber,a uniform optical frequency comb with a flatness within 3 d B is realized in the wavelength range of 0.3nm.Secondly,based on this structure,by optimizing the total cavity length and the external modulation method of the acousto-optic frequency shifter,a flat frequency sweep output with a single cycle loss of 0.54d B is achieved.2.The operating principle of the micro-ring is deduced,and the structure of the micro-ring is simulated by MATLAB and COMSOL.The output spectrum and dispersion characteristics of the download end of the multiple micro-rings in series and multiple micro-rings in parallel are compared and analyzed.3.The relationship between time delay and frequency is established by using multiple micro-rings in parallel.Finally,the optical frequency comb with equivalentβ₂of1.99×10⁵ ps² is realized.Based on this structure,a periodic time-frequency mapping with a slope of 1.09 ps/MHz between the time delay and the input signal frequency within the bandwidth range of 4GHz is completed,so as to realize fast frequency measurement.