Voigt wave investigation in the KGd(WO 4 ) 2 :Nd biaxial laser crystal

International audienceWe have investigated the Nd 3+-doped KGd(WO 4) 2 biaxial laser crystal for wave propagation directions in the vicinity of the optical axis at wavelengths tunable around 800 nm. The angular absorption distribution was found strongly anisotropic. Increasing absorption, the optical axis splits in two new ones able propagating unchanged a left or a right circularly polarized light and able propagating a circularly polarized Voigt wave with a linear spatial dependence. The intensities of the transmitted light in different configurations of polarizations were investigated. The angular displacement of the two optical axes versus the absorbed wavelengths was measured and explained with a single oscillator model. The light energy propagation was found distributed inside a crescent-shaped area