Polarization properties of lasing near an optical axis in the KGd(WO4)(2):Nd biaxial crystal
Résumé
Fluorescence and stimulated emission were obtained for propagation directions in the vicinity of the optical axis from the biaxial Nd-doped KGd(WO4)2 crystal. We visualized the peculiar role of the optical axis by fluorescence conoscopy. A fourth spectroscopic parameter due to the monoclinic symmetry was exhibited. Intra-laser-cavity conoscopy was performed in conjunction with the lasing in order to indicate the role of the elliptical modes. The lasing efficiency was found to be in agreement with the relative intensity of the left and right circular polarized components of the fluorescence near the optical axis.