Rare-earth-doped lanthanum–gallium–sulfide–oxide glasses as new optically operated materials

Illumination by pulses of second harmonic generation of picosecond Nd?YAG lasers at power densities of up to 200?MW?cm?2 has shown the appearance of photo-induced changes of the absorption in the transparent spectral range for lanthanum?gallium?sulfide?oxide (LGSO) glasses. Incorporation of the different rare-earth ions of 1% by weight substantially changes the observed photo-induced absorption. In particular, the additional photo-absorption is successively decreased by going from Nd3+ to Ce3+ rare-earth ions compared to the undoped LGSO glasses. Also, for Sm3+ ions with an enhancement of the pumping power density, it was even observed that the sign of the absorption changes. To explain the observed dependences, molecular dynamics and quantum chemical calculations were performed for the principal structural fragments of the glasses. The results observed allow us to consider the investigated materials as optically operated materials for the recording of information.