Holographic self-amplification in amorphous As55Se45 and As65Se35 film
s has been studied. Results on this amplification over a wide range of
initial diffraction efficiencies 10(-5)% < eta(0) < 1% are reported.
The degree of amplification increases with decreasing eta(0). At fixed
values of eta(0) and of the sample thickness, the maximum self-amplif
ication corresponds to a period Lambda = 2. 0 mu m of the grating holo
gram. An increase in the diffraction efficiency in the dark has been o
bserved for the first time in As-Se films.