Broadband 1.5-2.1 µm emission in gallo-germanate dual-core optical fiber co-doped with Er<sup>3+</sup> and Yb<sup>3+</sup>/Tm<sup>3+</sup>/Ho<sup>3+</sup>
Jakub Markiewicz, Marcin Kochanowicz, Tomasz Ragiń, Karolina Sadowska, Jacek Żmojda, Piotr Miluski, Jan Dorosz, Marta Kuwik, Wojciech A. Pisarski, Joanna Pisarska, Magdalena Leśniak, Dominik Dorosz
Abstract
The near-infrared emission in fabricated low-phonon energy, gallo-germanate glass, and double-core optical fiber has been investigated. Broadband amplified spontaneous emission (ASE) was obtained in optical fiber with cores doped with: 1 st - 0.2Er 2 O 3 and 2 nd - 0.5Yb 2 O 3 /0.4Tm 2 O 3 /0.05Ho 2 O 3 as a result of the superposition of emission bands from both cores corresponding to the Er 3+ : 4 I 13/2 → 4 I 15/2 (1 st core) and Tm 3+ : 3 F 4 → 3 H 6 /Ho 3+ : 5 I 7 → 5 I 8 (2 nd core) transitions. The effect of fiber length and pump wavelength on the near-infrared amplified spontaneous emission (ASE) properties has been analyzed for 1 m and 5 m optical fiber. The widest emission bandwidth (355 nm - 3 dB level) was obtained for a 5 m length optical fiber pumped by a 940 nm laser.