Phosphor‐in‐Ceramic‐Converted Laser‐Driven Near‐Infrared Light Sources for Multiple Intelligent Spectroscopy Applications

Abstract

Ultrabright broadband near‐infrared (NIR) phosphor‐converted laser diode (pc‐LD) as a light source is increasingly essential for improving the sensitivity and spatial resolution of intelligent NIR spectroscopy technologies. However, the performance of NIR pc‐LD is greatly hindered by the low external quantum efficiency (EQE) and poor thermal resistance of phosphor materials. Herein, a highly stable phosphor‐in‐ceramic (PiC) film deposited on high thermal conductivity substrate, in which the NIR‐emitting Ca3MgHfGe3O12:Cr3+ phosphor is incorporated into a glass‐crystallized Ca3Ga2Ge3O12 ceramic matrix, along with the formation of a new type PiC composite material with high efficiency, absorbance, and thermal conductivity, is designed and prepared. The obtained PiC exhibits an impressive EQE of 57.7%, high thermal conductivity of 17.1 W m−1 K−1, and the PiC wheel demonstrates a broadband NIR emission exceeding 5 W when excited by a 450 nm laser. Finally, a groundbreaking electrically driven pc‐LD device based on PiC achieves 1.6 W of NIR output, enabling multiple intelligent spectroscopy applications in archaeology and night vision imaging. This work paves the way for advancing broadband NIR light sources in a diverse range of photonic applications.