Abstract

An interesting aspect of echo signals that has been largely ignored is their temporal shape. This is not surprising, since echo shapes usually exhibit a complicated dependence on the characteristics of each excitation pulse and on the properties of the echo-producing material. However, as was first pointed out in the study of spin echoes¹ and recently rediscovered in the case of photon echoes,^2–4 in special cases, echo shapes essentially reproduce the shape (or time-reversed shape) of just one of the excitation pulses.

© 1984 Optical Society of America