稀土掺杂光学超晶格的自变频激光模型与应用

通过结合准相位匹配理论和空间分布自混频（或自倍频）激光模型提出了稀土掺杂光学超晶格材料自变频激光理论模型，该模型计入了弱聚焦的高斯光束空间分布，泵浦耦合以及非理想周期结构的影响，并应用该理论模型对Nd^3 离子掺杂非理想周期极化铌酸锂（Nd^3 :APLN)晶体同步自变频多波长激光进行了模拟计算，计算结果，尤其是阈值、可见激光总输出功率和同步可见激光谱线相对强度分布等与实验结果符合得很好，从而表明该模型的有效性。

Modeling of the Self-frequency-conversion Lasers in Rare-earth Doped Optical Superlattice Crystals and Its Application

Recently attention is focused on the quasi-phase-matched self-frequency-conversion (SFC) laser generations in rare-earth doped optical superlattice crystals, mainly because of their ability to generate multicolor lasers across the visible portion of the spectrum through a single crystal. We present a general model for quasi-phase-matched SFC lasers in rare-earth doped optical superlattice crystals by combining quasi-phase-matching (QPM) theory and the self-sum-frequency mixing (or self-frequency-doubling) laser patterns. The new model takes into account the TEM00 distribution of Gaussian beams with loose focusing, absorption and coupling of pump beams, and effects of imperfect periodical structures. Two types of errors: (1) random period errors and (2) linearly tapered period errors in the periodicity of these structures are analyzed to find their effects on the value of equivalent effective nonlinear coefficient and on the tuning curves of normalized conversion efficiency. Finally the model is applied to simulate the SFC laser properties in a Nd3+ doped aperiodically poled lithium niobate crystal. The calculated results, especially the threshold, the total visible laser output power and spectrum of relative laser intensity in the visible, agree well with the experiment, which indicates the validity of this model. Most significantly, the model presented explains and verifies the simultaneous laser generation of multiple visible wavelengths (686,605,542,482,441 and 372nm) from a single crystal.