中文摘要：

本文研究了倒Y型四能级系统中自发辐射诱导相干对探测场的色散和吸收特性的影响。在稳态条件下利用密度矩阵微扰理论推导出了密度矩阵的迭代解。数值分析了自发辐射诱导相干对线性和非线性折射率和吸收系数的影响,分析了泵浦场和耦合场偏离双光子共振对弱探测场色散和吸收特性的影响。研究发现自发辐射诱导相干使弱探测光的线性和非线性折射率增强,同时形成一个较宽的透明窗。在没有自发辐射诱导相干的情况下,泵浦场和耦合场偏离双光子共振对探测场的线性和非线性折射率影响明显,在有自发辐射诱导相干的情况下,泵浦场和耦合场偏离双光子共振使得探测场的线性透明窗变窄,非线性吸收增加。

英文摘要：

Effect of the spontaneously generated coherence on properties of the dispersion and absorption of the probing field in the inversed Y-type-four-level system was investigated. Under the stable state condition, and using the perturbation theory, the iterative solution of the density matrix was obtained. Effect of the spontaneously generated coherence on the linear-and nonlinear-refractive index and absorption was analyzed numerically. Effect of the coupling field and pumping field off the two-photon resonance on the properties of the dispersion and absorption of the probing field was analyzed. We found that the linear-and nonlinear- refractive indexes were enhanced via spontaneously generated coherence. At the same time, a broad transparency window was formed. When there is no spontaneously generated coherence in the system, the effects of the pumping field and coupling field off the two-photon resonance on the linear and nonlinear dispersion are great; and when there is spontaneously generated coherence in the system, that the pumping field and coupling field are off the two-photon resonance and make the linear transparency window narrow and nonlinear absorption enhance.