Infrared to visible frequency upconversion temperature sensor based on Er3+-doped PLZT transparent ceramics

Infrared to visible upconversion in erbium doped lead lanthanum zirconate titanate (PLZT) transparent ceramic is reported for the first time. Intense green upconversion emissions around 534 and 565 nm originating from the thermally coupled levels ²H_11/2 and ⁴S_3/2 are observed. The mechanism responsible for excitation of these emitting levels is sequential two photon absorption based on the temperature dependence of the emissions ratio, a high temperature (up to 610 °C) sensor is proposed, with various advantages over the existing glass-based sensors, such as higher thermal and mechanical resistances, better chemical stability and lower cost fabrication.