6. Conclusion

Fluoride glass waveguides provide access to spectral ranges where silica is ineffective. This is the case with TR-doped laser fibers, which have been demonstrated down to wavelengths close to 4 μm, in some cases with significant output powers (e.g.: 30 W at 2.9 μm with Er ³⁺ ) or fibers for supercontinuum generation down to around 5 μm in the infrared.

In the field of planar waveguides, the target applications are optical amplification and displays. Future technological developments are likely to concern the material itself, with control of impurity levels and crystallization mechanisms still open to improvement, as well as fiber and waveguide production techniques.

Imagining new pumping techniques for these optical devices is another way forward.