Towards all-fiber optical coolers using Tm-doped glass fibers

We present our experimental and theoretical results of optical cooling in Tm-doped glass fibers as optical cooler pumped by single-mode, high efficiency and high power Tm-doped glass fiber lasers. The effects of impurities including OHabsorption and transition metals have been investigated systematically using different purified glasses for fiber fabrication. Our experimental results of spectroscopic measurements show temperature drops of more than 30 degrees from room temperature with pump powers of less than 3W. The results are in good agreement with theoretical simulation.