Last time I talked here was about four months ago and at this point, I was almost in darkness regarding the project I will lead during the next years and which I already had to introduce. But now things have changed. What happened? Well, obviously a few months have passed and work has been done. More important however, the first GraWIToN School took place and for the first time I could figure out the greatness of the European project. The School took place at the European Gravitational Observatory (EGO) for three weeks and had several purposes which, in my opinion, have been achieved in a wide part.

First it gathered for the first time all the ESRs (as well as a lot of other students who should not be omitted) who will share the task to become ambassadors for the project in the next years. We met, we exchanged, we worked and, above all, we enjoyed together, out but also for a wide part in the frame of the School. These three weeks helped to develop an actual group spirit that will surely come useful for the future of the project.

Of course meeting people wasn’t the sole target of these three weeks, and who says School also says courses. So we had courses. Lots of courses. Far too many for all of them to be remembered. Well, it is a good thing it wasn’t the purpose then. During these weeks, about 20 researchers came to teach or to discuss about their research, and the least that can be said is that the area of knowledge covered was wide enough for everyone to find something interesting about it. The real achievement of these courses was in my opinion to open the mind of the young researchers on how deep and branched the project is beyond their own research field. As far as I am concerned, these courses were a success both regarding what they brought me for my own research and what they showed about the wider frame.

Finally, thanks to the location of the school, I had the immeasurable luck that some of the other ESR already had: Meeting VIRGO. There is probably no need to praise its greatness here, but I think that actually seeing it gives a whole new dimension to our projects, making us believe that sooner or later (and likely quite soon) all these talks will eventually end up to something actual and with no doubt revolutionary.

Well, these were only three weeks out of four months and I claimed that I worked on my project too so I am a bit liable to talk about my own progress in order to deserve my privileged position.

As a reminder, I’m working on silicate bonding which is a bonding technique very promising for optical applications. The technique was already used for assemblies in the previous generation of detectors due to good mechanical properties, but within the frame of this project, the interest switch towards its optical properties to solve issues met in the laser industry. Therefore, the new materials of interest are host materials for the gain media of solid state laser. First trials have been made and proved that the bonding could occur despite the different chemistry which is actually very promising. A whole process of characterisation and optimization of the bond is about to start in order to assess that the optical properties of the final bonded component fit the requirements and that the bond can last during its working conditions. This process will involve physical tests as well as some simulations and I can’t wait to be back to present some results that will define the upcoming ways of improvements.

Grégoire Lacaille