Infrared laser stimulated broadband white emission of transparent Cr:YAG ceramics obtained by solid state reaction sintering

摘要

In the present work, the Light Induced White Emission (LIWE) was investigated as one of the sources of laser loss in transparent Cr:YAG ceramics. We have found that transparent Cr:YAG ceramics is capable of generating bright LIWE at excitation powers above a certain threshold. Intensity of LIWE strongly depends on the excitation power and ambient pressure. The host temperature estimated from Cr3+ luminescence was found to be below 600 degrees C, while the most intense white emission was found between 50 and 400 degrees C. The mechanism of the laser induced white emission was discussed in terms of Intervalence Charge Transfer (IVCT) in chromium mixed valence pair.