FEMTOSECOND TIME-AND-SPACE DOMAIN HOLOGRAMS - DIFFRACTION ON THE EDGEOF TIME

We study the diffraction properties of time-and-space domain holograms stored with femtosecond light pulses with a coherence length much sma ller than the lateral geometrical dimension of the hole-burning sample . We show that one can observe diffraction of read out beam on the vir tual 'time edge' separating the spatial regions where the delay betwee n the reference and the object pulses is either positive or negative. We also demonstrate that by placing a Fourier-transforming lens in the beam diffracted from the 'time edge' a spatial intensity pattern prop ortional to the homogeneous hole-burning spectrum is observed.