Light Delivery, Acoustic Read‐Out, and Optical Thermometry Using Ultrasound‐Induced Mechanoluminescence and the Near‐Infrared Persistent Luminescence of CaZnOS:Nd3+

Abstract Light emission from CaZnOS:Nd 3+ by high‐intensity ultrasound excitation is demonstrated. Acoustic power and duty ratio enable simultaneous control of the degree of (local) thermo‐acoustic heating in isothermal or nonisothermal conditions. The Nd‐related photoemission provides direct thermometric feedback at an absolute sensitivity on the order of 10 −4 K −1 , within the physiological temperature range. From the individual temperature dependence of persistent luminescence and mechanoluminescence, both effects are attributed to a heterologous de‐trapping mechanism. In addition to acoustic heating and optical thermometry, this enables optical information storage and smart labeling with optoacoustic read‐out.