Ultra-Efficient GAGG:Cr3+ Ceramic Phosphor-Converted Laser Diode: A Promising High-Power Compact Near-Infrared Light Source Enabling Clear Imaging

Near-infrared (NIR) light is widely used in fields such as organic components detection and biological imaging, due to its strong tissue penetration and non-destructive characteristics. To improve the detection sensitivity and spatial resolution of bioimaging, it is important to obtain a new NIR light source with good thermal stability, high efficiency, and ultra-high optical output power, which currently remains a great challenge. In view of this, a Gd3Al2Ga3O12:Cr3+ (GAGG:Cr3+) NIR ceramic phosphor is proposed in this study. By optimizing the preparation process of GAGG:Cr3+ ceramic phosphor and the concentration of Cr3+ ions, high external quantum efficiency (EQE = 70.1%) and excellent thermal stability (96.8%@150 degrees C) are achieved. After coupling the GAGG:Cr3+ ceramic phosphor with a blue light-emitting diode (LED), the electro-optical conversion efficiency of the NIR ceramic phosphor converted LED (NIR-cpc-LED) reaches 31%@20 mA, which is higher than the previously reported values. Moreover, when coupled with a blue laser diode (LD), the optical output power of the NIR-cpc-LD reaches as high as 1652.6 mW@5.5 W. Therefore, GAGG:Cr3+ NIR-cpc-LD not only shows a great prospect in practical applications, but also provides a new solution for high-power compact NIR light sources.