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 一類典型的系統(tǒng)是電偶極躍遷構(gòu)成a型的系統(tǒng),條件是兩低能級(jí)壽命很長(zhǎng), a型兩偶極躍遷發(fā)生雙光子共振。
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 第二章中我們使用了yelin等提出的具有非相干泵浦的開放v型三能級(jí)系統(tǒng)模型,通過(guò)密度矩陣運(yùn)動(dòng)方程給出了該系統(tǒng)的定態(tài)非線性解析解的普遍表達(dá)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:研究了級(jí)聯(lián)三能級(jí)系統(tǒng)中的相位共軛極化拍頻光譜術(shù).發(fā)現(xiàn)其對(duì)能級(jí)差的測(cè)量精度決定于光學(xué)躍遷的均勻增寬.在符合拍頻條件時(shí),兩獨(dú)立光源拍頻的頻差可以超出激光線寬,激光絕對(duì)頻率的測(cè)量精度可達(dá)到與激光線寬同一量級(jí)
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,在多年的電信增值行業(yè)數(shù)據(jù)挖掘商業(yè)應(yīng)用研究的基礎(chǔ)上,本文論述了數(shù)據(jù)挖掘商業(yè)應(yīng)用平臺(tái)的三層(即客戶層,中間層和數(shù)據(jù)服務(wù)層)體系結(jié)構(gòu),并對(duì)各層的主要功能進(jìn)行了詳細(xì)的闡述。