La-doped PMN–PT transparent ceramics with ultra-high electro-optic effect and its application in optical devices

Abstract

Transparent electro-optic (EO) ceramics of La-doped 0.75Pb(Mg1/3Nb2/3)O3–0.25PbTiO3 (0.75PMN–0.25PT) were prepared successfully. High transparency of 69% in the near-infrared (IR) wavelength (1550 nm) was achieved at 2 mol% La doping, meanwhile it shows an extremely high quadratic EO coefficient of 45.4×10−16 m2·V−2, which is indispensable for applications in EO devices. The distribution of a polar nanodomain structure of the samples experiences disorder–order–disorder evolution in a La doping range. It is found that a parallelly-stacked polar nanodomain structure with an easier and faster polarization switching in the 2 mol% La-doped sample suggests that an ordering distribution of polar nanoregions would be critical to inducing large EO effect, transparency, and piezoelectric response. A triple-cavity tunable optical filter (TOF) with a single transmission peak and a tuning voltage below 30 V in a tuning range of 190–197 THz was designed based on our ceramics. The work is believed to bridge the relationship among doping-engineering, EO properties, and polarization behavior, which would guide the further optimization of transparent EO ceramics.

Keywords

• pb(mg1/3nb2/3)o3–pbtio3 (pmn–pt) electro-optic (eo) ceramics
• transmittance
• domain reversal
• polarization
• tunable optical filter (tof)