Phosphate glass combines a protracted life time of Er3+ upper laser level with effective Power transfer in between Yb3+ and Er3+ ions and decreased upconversion losses, thus providing economical Procedure in passively Q-switched diode-pumped and flash-lump pumped lasers used in range-finders.language �?中国 韩国 韩国 韩国 韩国 韩国 �