Determination of the effective trap density of Ta: KNbO 3 and BaTiO 3 at 823 nm using the shallow trap model

Abstract

Using the shallow-trap model, the effective trap density in Ta: KNbO 3 and BaTiO 3 is measured at 823 nm using a laser diode and is compared with values at 514.5 nm. A reduction of trap density is shown at the longer wavelengths. Exponential gain coefficients are given as a function of geometry for both crystals in the near-infra red. The effect of angular bandwidth on gain and its effect on image amplification is also examined.