On the information storage time with stimulated photon echoes in gases on the [formula omitted] transition

Abstract

The electric field strength of a stimulated photon echo generated in a gaseous medium on the transition with the electronic total angular momentum change J b= 1 2 →J a= 1 2 is calculated in the case when the spectral width of both exciting pulses greatly exceeds the hyperfine splitting frequencies Δ a and Δ a ( Δ a ⪢ Δ b ) of both the ground a and excited b atomic states. It is known that if the recording pulses have collinear polarization vectors and if the inequality | Δ b τ 1-2 πl| ⪡1 ( l=0,1,...) involving the time in terval τ 1 between them is satisfied the information storage time τ 2 depends on the information restoration time τ 1. The information storage time, instead, is much greater if | Δ a τ 1- π(2 n+1)| ⪡1, than in the case | Δ a τ 1-2 πm| ⪡1 ( n, m = 0, 1, 2,...). This property of a stimulated photon echo signal may be employed for the selection of even (or odd) elements from the pulse trains.