“…Among RE ions, Pr 3+ is an attractive optical activator, which offers the possibility of simultaneous blue, green and red emission for laser action as well as IR emission for optical amplification [1]. 1.3 m Pr 3+ : ZBLAN optical fiber amplifier has been demonstrated [2]. 491, 520 and 635 nm upconversion lasers have been realized in Pr 3+ : ZBLAN under infrared laser pump [3] indicating that it is an attractive upconversion laser media.…”