Hot emission in Nd3+/Yb3+:YAG nanocrystalline ceramics

A visible emission of Nd3+ in the double doped Nd/Yb:YAG nanocrystalline ceramics was observed under intense CW excitation by 976 nm laser diode. The observed emission is assigned by us to hot emission and it strongly increased with temperature. Its intensity exhibited long emission build-up times (of an order of seconds) after turning on the excitation source. The intensities of hot emission of Nd3+ ion increased with the excitation power demonstrating the IN dependence. It was found that N was proportionally dependent on the energy distance ΔE=Eemhot−E(4F3/2). The effect of Yb3+ concentration on hot emission intensity was also noticed. No Nd3+ emission from 4F3/2 level under indirect 976 nm excitation was observed. The mechanisms leading to the visible hot emission in Nd/Yb:YAG nanocrystalline ceramics are discussed.