Rare-earth gallate optical fibers for Mid-InfraRed optical applications
Résumé
The ability to produce robust fiber-based integrated optical systems operating over a wide spectral domain from the ultra-violet up to mid-infrared is one of today’s key challenges in photonics. Over recent decades, several glass systems such as fluorides, heavy metal oxides and chalcogenides appeared to be promising alternatives to SiO2 glasses, but have not yet been able to compete with its high thermal robustness and remarkable mechanical assets. Following an original approach, this work reports on the production of light guiding fibers from rich rare-earth gallium oxide-based glass compositions. The impact of the addition and the nature of rare earth (RE) ions to improve the delay to crystallization will be discussed. These materials exhibit relatively high vitreous transition temperatures (~ 735 °C), improved surface micro-hardness and low phonon oxide glass matrix. Those vitreous systems offer an excellent optical transmission extending from ultraviolet wavelengths (~ 0.280 μm) up to 6 μm. They also show a relatively high third order polarizability
and high RE mid-infrared emitting centers solubility. This unique combination of superior thermal, mechanical and optical properties represents a promising alternative for the development of highly robust power scaled fiber devices operating from the UV up to the challenging 2 – 5 μm optical domain.