Some implications of the nonlinear properties of SASD crystals

The paper deals with the results of optical and EPR measurements performed on single-crystallineand powdered samples of sodium ammonium sulphate dihydrate (SASD) and sodium ammonium selenate dihydrate (SASeD) doped with Cr3+ and irradiated with X-rays. It is shown that for samples doped with Cr3+ one detects in the optical spectrum, apart from the existence of two broad transmission bands, yet another narrow band, corresponding to the 4A2g(F) › 4T1g(F) transition, which suggests that such samples can potentially exhibit laser action. The EPR spectra of X-ray irradiated pure samples of SASD crystals indicate that a variety of paramagnetic centres (NH4- , SO4-n ) are easily induced by irradiation. The concentrations of these centres are in close relation with the dose of irradiation. The observed relation can be used for dosimetry purposes.