7. Conclusion

In the field of crystals, and particularly crystalline fibers, decisive advances have been made, but the context remains highly evolving. New applications based on new concepts or responding to new needs are already being tested (fiber lasers, fiber detectors). The pre-formed crystals (fibers, wafers) and components required for these developments still need to be developed, building on what has already been achieved, but also revisiting and extending the techniques already perfected.

Significant developments carried out by the scientific community and more particularly in France (Institut Lumière matière (ILM) UMR 5306, Luminescence team in Lyon, and Cyberstar (ECM) in Grenoble) are :

• Improved stability of the pulling head (translation system) of the micro-pulling-down machine, resulting in stable diameter fibers...