Luminescence properties of highly Cr co-doped Nd:YAG powder produced by sol–gel method

We examined luminescence properties of highly chromium co-doped Nd:YAG powders fabricated by the sol–gel method. Though the maximum luminescence intensity of Cr:YAG was at 3.0 mol% of Cr3+ concentration, we found that the enhancement effect on Nd:YAG by co-doping Cr3+ was continued until 6.0 mol% of Cr3+ concentration. This phenomenon is well-explained by a simple energy transfer model derived from the rate equations between Cr3+ and Nd3+. The enhancement of sensitization for Nd3+ activator by high co-doped Cr3+ is very effective for making a miniaturized or thin film-type solar laser.