Accession Number : ADA131691

Title :   Time Dependent Pulse Amplification in a Three Level Gas.

Descriptive Note : Progress rept. 1 Jan-31 Dec 80,

Corporate Author : BROWN UNIV PROVIDENCE RI DIV OF ENGINEERING

Personal Author(s) : Morse,T F ; Tsai,Tsung-Ming

PDF Url : ADA131691

Report Date : Dec 1980

Pagination or Media Count : 47

Abstract : The time dependent density matrix equations have been solved in conjunction with the field amplitude equations for a three level optically pumped gas. The solutions are valid in the limit in which the pumping pulse is longer than the dephasing time of the system and true coherent effects may be neglected. It is assumed that the FIR field is smaller than the pump field, and saturation effects associated with this field are absent. In the limit in which the pump pulse is resonant, particularly simple results for the FIR field amplification may be obtained. The solutions exhibit the dependence of the FIR output pulse on the shape of the input pulse. Further, as a consequence of non-linear saturation effects on the pump pulse transition, the FIR pulse is initially created with two peaks, one associated with the leading edge and one with the trailing edge of the pump pulse. As amplification on the FIR transition and pump absorption increase, these two peaks merge.

Descriptors :   *Argon, *Laser pumping, *Pulse amplitude, Gas dynamics, Optical pumping, Pulse rate, Nonlinear differential equations, Mathematical analysis

Subject Categories : Lasers and Masers
      Plasma Physics and Magnetohydrodynamics

Distribution Statement : APPROVED FOR PUBLIC RELEASE