Quantum-efficiency of praseodymium doped Ga:La:S glass for 1.3 μm optical fibre amplifiers

• Published in: IEEE photonics technology letters 1994, Vol.6 (5), p.609-612
• Main Authors: HEWAK, D. W, MEDEIROS, J. A, SAMSON, B, BROWN, R. S, JEDRZEJEWSKI, K. P, WANG, J, TAYLOR, E, LAMING, R. I, WYLANGOWSKI, G, PAYNE, D. N
• Format: Article
• Language: English
• Subjects: Exact sciences and technology; Fundamental areas of phenomenology (including applications); Laser optical systems: design and operation; Optics; Physics; Resonators, cavities, amplifiers, arrays, and rings
• ISSN: 1041-1135; 1941-0174
• DOI: 10.1109/68.285556

The gain of Pr super(3+)-doped ZBLAN fibre amplifiers is hindered by a poor quantum efficiency due mainly to a high rate of multiphonon decay. Sulphide-based glasses ameliorate this problem through a higher radiative rate and lower nonradiative rate. In this letter, Pr super(3+)-doped Ga:La:S glass has been evaluated spectroscopically in bulk and fibre form for its quantum-efficiency at 1.3 microns. Measurements reveal that absorption bands are broadened and the effective separation between the super(1)G sub(4) and super(3)F sub(4) level is reduced compared to ZBLAN glass. Judd-Ofelt analysis and the theory of multiphonon-decay now predict efficiencies of 80%, while 58% is measured. Oxide impurities are shown to play a key role in quenching of the radiative emission.