Time Domain Holography

Abstract

It is acknowledged that inhomogeneous absorption bands consisting of narrow homogeneous zero-phonon lines (ZPL) can be used for the purpose of optical data storage in the frequency dimension /1/. Persistent spectral hole-burning (PSHB) /2,3/ has made it feasible to preserve the recorded frequency domain information for a practically unlimited period of time. Via PSHB the inhomogeneous distribution function of the resonance frequencies of the impurity zero-phonon lines can be altered in an almost arbitrary fashion. This, in turn, makes it possible to manipulate the absorption coefficient and correlated to it index of refraction of the optical storage media. On this basis it has been proposed to use PSHB for the shaping of laser pulses via Fourier synthesis /4/. Holographic storage of time domain optical signals in PSHB media was proposed by Mossberg /5/. In the first experiments on the PSHB time domain holography the reproduction of various temporal shapes of picosecond pulses was demonstrated in dye doped polymers cooled to liquid helium temperature /6/. Earlier Zuikov et al. observed correlation between the temporal shapes of nanosecond excitation laser pulses and photon echo signals /7/. Since that time a variety of experiments on time domain holography in different resonant media have been reported (see /8/ and references therein).