The photoluminescence of Er3+ ions in thin films of amorphous silicon has b
een studied under conditions of intense pumping. A superlinear increase in
the amplitude and a shortening of the photoluminescence relaxation times ar
e revealed at a pumping intensity above 200 kW/cm(2). The data obtained are
explained by the threshold ''switching-on'' of the superluminescence mecha
nism. (C) 2000 MAIK "Nauka/Interperiodica".