THE DEPENDENCE OF HOLE WIDTH AND DEPTH ON BURNING LASER DURATION

The evolution of power broadening in the hole-burning process is considered. Under a strong field, a deep hole with HWHM less than 0.8K (K is the Rabi frequency) can be burnt if a pi-pulse is applied. The hole width reaches its minimum with a near pi-pulse if the ratio T2/2T1 of the two level system is less than 0.78. The minimal width is much narrower than the steady-state one predicted by the optical Bloch equation and comparable to the narrowest that the modified Bloch equation may give.