The Research And Application Of Spectral Hole Burning Based On Crystal Tm³⁺: YAG

With the deep understanding of the spectral hole burning theory analysis, the applicationof spectral-hole burning technology is gradually mature, especially in radar signal processingand ultra broadband radio frequency signal spectrum analysis. The conventional methodproves to be unsatisfied the requirement analyzing signals spanning several GHz duringmilliseconds. However, spectral-hole burning technology can meet the above requirements byusing the hole burning crystal material which has as high as dozens of GHz inhomogeneousbroadening line width, and a few hundred KHz homogeneous broadening line features such aswide. As a consequence, spectral hole burning become one of the hot issues of the research.Spectral-hole burning characteristics and its application based on Tm3+: YAG crystal arestudied, moreover, the physical mechanism of the interactions between electromagnetic wavesand spectral-hole burning (SHB) crystal materials is investigated in this dissertation. Firstly,we summarize the study progress on spectral-hole burning and photon echo technology.Optical Bloch equation is deduced based on density matrix. The formation of spectral hole isanalyzed Based on Maxwell-Bloch equation. Then we introduced the perturbation theory, thespectral-hole burning model is established based on the perturbation theory. According to themodel, we performed the experimental demonstration in Tm3+: YAG within cryogenictemperature about the dependence of spectral-hole width on chirp rate of the reading laser.Lastly, an ultra wide bandwidth, high time bandwidth product of arbitrary waveformgenerator based on the theory of stimulated photon echo is proposed. The details are describedas follows:1. The theoretical model of spectral hole burning mechanism of Tm3+：YAG crystal wasestablished based on the perturbation theory. We bridge the gap between spectral-hole burningand three-pulse photon echo based on Perturbation Theory. Solutions of the Liouvilleequation carried out three order perturbation results. According to the theoretical result, whenthe first optical pulse and the second optical pulse overlapped in time where one is a replica ofthe other, a spectral grating with just one fringe will be created. When the Frequency-chirpedreading laser diffracts off of the newly created spectral grating, the detector will sense thetransmitted signal which is the spectral-hole. We also called the transmitted signal the zeroorder diffraction of photon echo.2. The characteristic of spectral hole burning In Tm3+: YAG based on establishedtheoretical model is investigated. According to the model, spectral-hole width has adependence on the chirp rate of the reading laser. When the chirp rate is slow relative to thespectral features of interest, the spectral hole closely mapped to time domain, and vice for afast chirp rate the distortions are observed. The results follow Maxwell-Bloch model, and theresults are also in good agreement with the experimental results. 3. An ultra wide bandwidth, high time bandwidth product of arbitrary waveformgenerator based on the theory of stimulated photon echo is proposed. Firstly, the pulsecompression technology is investigated in detail based on photon echo. Simulation resultsexhibits the pulse compression with the time width of68ps, and the spectral bandwidth is15GHz. Through combination of eighteen compression pulse, we gain the time bandwidthproduct of arbitrary waveform signals up to15000.