Therefore, in two-level schemes, the state of population inversion cannot be reached. The two level- pumping scheme is shown in Fig. 10.6. The widely used pumping schemes are (a) Three-level pumping scheme, and (b) Four-level pumpinganbsp;...
|Title||:||Engg Physics (Uptu 2007)|
|Publisher||:||Tata McGraw-Hill Education - 2007-07-01|