One typical model for cpt is the a type three - level system when the life times of the ground levels are long enough and the coherent driven transitions are on the two - photon resonance 一类典型的系统是电偶极跃迁构成a型的系统,条件是两低能级寿命很长, a型两偶极跃迁发生双光子共振。
In chapter 2 , we use an open v - type three - level system model with incoherent pump put forward by yelin , and give a universal nonlinear analytical solution of the steady state by density - matrix equations of motion 第二章中我们使用了yelin等提出的具有非相干泵浦的开放v型三能级系统模型,通过密度矩阵运动方程给出了该系统的定态非线性解析解的普遍表达式。
Abstract : we have studied the polarization beats spectroscopy with phase - conjugation geometry in a cascade three - level system . it was found that the accuracy for the energy - level difference measurement is determined by the homogeneous linewidths of the optical transitions . under the condition for the occurrence of beating , the frequency difference of the beat between two independent light sources could exceed the laser linewidth . the measurement accuracy for laser absolute frequency could reach the same order of magnitude as the laser linewidth 文摘:研究了级联三能级系统中的相位共轭极化拍频光谱术.发现其对能级差的测量精度决定于光学跃迁的均匀增宽.在符合拍频条件时,两独立光源拍频的频差可以超出激光线宽,激光绝对频率的测量精度可达到与激光线宽同一量级
Secondly , according to the long - term research on the data mining commercial application of telecommunication increment profession , this article elaborate three - level systems structure of the data mining commercial application platform , namely the customer level , the intermediate level and the data service level , and make detailed description to each level ’ s main function 其次,在多年的电信增值行业数据挖掘商业应用研究的基础上,本文论述了数据挖掘商业应用平台的三层(即客户层,中间层和数据服务层)体系结构,并对各层的主要功能进行了详细的阐述。