Influence of F- on stark splitting of Yb3+ and the thermal expansion of silica glass

A local phosphate/fluoride environment of Yb3+ was created in silica glass using a multi-step method. The influence of F-on the Stark splitting of Yb3+ in Al3+/P5+/F- co-doped silica glass was studied at room-temperature, in addition to its effect on the thermal expansion performance of the glass matrix. The results indicate that Yb3+ ions in Al3+/P5+/F- co-doped silica glass have a larger Stark splitting energy of F-2(7/2) compared to Al3+/P5+ co-doped silica glass. Moreover, a larger integrated absorption cross-section (34.58 pm(2) x nm), stimulated emission cross-section (0.63 pm(2)), and better thermal expansion performance (1.3062 x 10(-6) K- at 100 degrees C) are achieved in Al3+/P5+/F- co-doped silica glass. Finally, different function mechanisms of F-in silica and phosphate glasses were analyzed and the F-Si bond was used to explain the results in silica glass. The combination of low refractive index, large Stark splitting energy of F-2(7/2), and small thermal expansion makes Al (3+)/P5+/F- co-doped silica glass a preferred material for large mode area fibers for high-power laser applications. Published by AIP Publishing.