Research

We have fabricated CaYAlO4 single crystals doped with chromium (Cr) and neodymium (Nd) using a technique called the floating zone melting method. By appropriately controlling the fabrication conditions, high-quality red transparent crystals were obtained (Fig. 1). The crystal has a very wide absorption range from the ultraviolet region to the visible region, and shows sufficient absorption even at the wavelength where the energy of sunlight is at its maximum (Fig. 2). We have also found that the absorption is 70 times or more that of conventional materials such as Cr and Nd:YAG. These properties are unique to the newly developed crystal and not found in existing materials. We have also demonstrated that neodymium can emit light upon excitation in the absorption band of chromium due to its fluorescence properties (Fig. 3). Based on this result, it is expected to convert solar energy into laser light with high efficiency.