Pair-Emission-Induced Near-Infrared Lasing from Ceramic Ga:LaCrO<inf>3</inf> Microcrystals at Room Temperature

Lasing is observed in microcrystals of the Ga:LaCrO3 (LaCr0.5Ga0.5O3) perovskite system due to the pair emission of the Cr3+ ions, with a lifetime in the sub-nanosecond range. Lasing due to pair emission is difficult to achieve in single-crystal materials because of the difficulty in obtaining the dopant's compositional uniformity. This captivating ceramic material reveals an appreciable lasing profile with a 488 nm laser pumping. Characteristic laser emission centered at 740 nm is observed, with a linewidth of 2.09 nm and a threshold power of 73 W cm−2 at room temperature. Photoluminescence (PL) spectra show enhanced lasing characteristics at low-temperature ranges. The time-resolved PL spectrum of the sample illustrates a sub-nanosecond lifetime of which 99.2% of the lifetime contribution is from pair emission. The short lifetime can be attributed to the high concentration of the Cr3+ ions, which enhances the Cr3+–Cr3+ exchange interaction, and pair emission, which is evidenced by an electron spin resonance study.