Photon echo as a method for the spectroscopy of crystals (review)

Vladimir S. Lobkov, S. A. Moiseev, E. I. Shtyrkov

В. В. Самарцев

State of the art of optical coherent spectroscopy of doped solids that are promising as information carriers for optical processors is reviewed. Special attention is paid to optical echo spectroscopy of doped crystals classified as the Van-Vleck paramagnets where the long-lived stimulated echo is observed with the optical-memory time reaching several hours at low temperatures. Modern elaborations of optical echo processors based on this echo phenomenon are discussed. Physical principles of femtosecond echo spectroscopy and coherent four-wave mixing spectroscopy are formulated. The abilities of these methods in the diagnostics of fast processes at room temperature are illustrated using examples of a doped polymer films. The results of elaborations of a new branch of optical spectroscopy (biphoton spectroscopy) are also presented. The advantages and possible applications of this method are demonstrated using an example of two crystals (Er 3+ :YAG and Cr 3+ :Al 2 O 3 ).

Robert N. Schwartz

Kiwan Jang, Il-Gon Kim, Sungtae Park

Optical dephasing in a number of crystalline samples of Y 2 O 3 : Eu 3+ prepared by two different crystal-growth techniques were measured using two pulse photon echo method. For crystals prepared by a laser-heated pedestal growth, we report the dephasing rate, 1/ T m , at 1.4 K is up to two orders of magnitude faster than that previuosly reported for the flame fusion growth crystal. The spatial dependence of the optical dephasing rate, measured by TPPE (two-pulse photon echo), tells that the environments of echo producing ions at least highly depend on the spatial position which can not be detected by conventional laser spectroscopy techniques, suggesting two-pulse photon echo experiment can be served as a tool for probing the uniformity of the samples.

Niklas Christensson, Benjamin Dietzek, Arkady P. Yartsev +1 more

A.I. Alekseyev