With the transient solutions of optical Bloch equation

dependences of hole width and depth on the burning pulse duration have been discussed for spectral hole burning of two-level system.With a strong and short π pulse

a deep hole may be burnt.Its width is much narrower than the steady state one predicted by optical Bloch equaion.While burning power density is weak

hole depth will be exponentially dependent on burning time.Modification of the Bloch equation does not significantly affect the results of above mentioned two cases.Based on the behavior of spectral hole burning of two-level system

situations of persistent hole burning and photon gated spectral hole burning have also been considered.