Erbium and ytterbium co-doped phosphate glass has a broad application because of the excellent properties. Mostly, it is the best glass material for 1.54μm laser due to its eye safe wavelength of 1540 nm and high transmission through atmosphere. It's also suitable for medical applications where the need for eye protection may be difficult to manage or diminish or hinder essential visual observation. Recently it is used in optical fiber communication instead of EDFA for its more super plus. There is a great progress in this field. Erbium Glass doped with Er 3+ and Yb 3+ and suited to applications involving high repetition rates (1 - 6 Hz) and being pumped with 1535 nm laser diodes. This glass is available with high levels of Erbium (up to 1.7%). Erbium Glass doped with Er 3+, Yb 3+ and Cr 3+ and suited to applications involving xenon lamp pumping. This glass is often used in laser range finder (LRF) applications.