Population and photorefractive-like index gratings in semimagnetic semiconductors

Summary form only given. We present a case with instantaneous recording of microsecond duration gratings in CdMnTe semimagnetic semiconductors when the laser frequency is tuned near the band edge of the semiconductor medium. In such a case the photo-generated carriers are very efficiently trapped on Mn/sup 2+/ sites, which allows the generation of a grating of fixed negative charges if an interference pattern illuminates the crystal. Neutrality requires the existence of a hole grating, which then creates a hole induced refractive-index grating.