Efficiency and uniformity considerations in optical coherent transient devices

Abstract

The efficiency and uniformity of photon echoes are investigated in optical coherent transient sequences using temporally overlapped linear frequency-chirped programming pulses. Distortions in the power spectrum of the programming pulses due to edge effects are found to cause fluctuations in echo efficiency as a function of echo time delay. Smoothing the edges of the programming pulse envelopes is found to significantly reduce distortion in the power spectrum of the pulses, which leads to echoes that are both more efficient and more uniform than those generated by pulses without smoothed edges. The effect of programming pulse strength on echo efficiency and uniformity is shown and discussed through simulations for an optically thin medium and through experiment in Tm 3+ : YAG at 4 K.

Preparation of inverted medium and processing in the inverted medium

“…In this paper, smoothed chirped pulses, which consist of a linear chirp with a square amplitude envelope sandwiched between rising and falling edges smoothed by hyperbolic phase and amplitude functions, are used for population inversion. A smoothed chirp provides uniform inversion over nearly the full bandwidth of the chirp [20].…”

Controllable photon echo phase induced by modulated pulses and chirped beat detection

“…[5] However, geometric phase research is still in its infancy and the technique of detecting geometric phase by using photon echo is not perfect. [6] Therefore, it is meaningful to introduce geometric phase into the photon echo research [7][8][9] to detect the geometric phase and the phase change of the photon echo.…”