Faraday effect of BSO and BTO crystals doped with Cr, Mn and Cu

The influence of both photochromic doping and photochromic transitions on t he effect of magnetooptical rotation (Farady effect - FE) of undoped and do ped with Cr, Mn and Cu Bi12SiO20 (BSO) and Bi12TiO20 (BTO) crystals is stud ied. The present results show, that Cr, Mn and Cu increase the FE. The infl uence of Cr, whose affect on the optical activity (OA) of BSO is most signi ficant, here is too negligible (Verdet coefficient (V) increases only with 1-2 % in the range 700 - 590 nm). The Mn-doping of BSO led to a V-increase with about of 11 % in the range 400 - 700 nm, as at 460 nm the relative inc rease of V reaches to about 30 %. The influence of Cu on FE in BSO (likely the case of the natural optical rotation) is again significant. Thus, the i nfluence of V in the case of BSO:Cu is about 18 % in the range 700 - 480 nm as reaches 28 % in the shortwave region at 480 nm. However, in BTO:Cu (0.0 2 mol.% Cu) the influence of Cu is opposite in respect of both effects. Now the values of V increase with 21 % at 630 nm, 22 % at 590 nm, 42 % at 520 nm, and 73 % at 480 nm in comparison to BTO-undoped.