ESR1My first month as a PhD student at the European Gravitational Observatory in the frame of the GraWIToN project went really well.
I had a good welcome from my colleagues, they have been very helpful to answer my questions on the project and also to help me with all the administration issues that you have to deal with when you start a new job and you settle down in a new country.
They also made me visit all the installations: that is really impressive and interesting. Making such a huge interferometer working and trying to be such precise is very challenging!
As always while starting a project, I logically spent most of the first week to read some documentation, read the reports of what have been done before I arrived. In parallel I discussed with my supervisor about what I am going to do in a short term but also medium and long term.
It was quite easy to have an overview of what I am expecting to do during the time that I will spend here and all the intermediate steps to get there, but it was more difficult to remind all the details that he told me. I think I may have missed some but, luckily, my colleagues are always here to answer my questions. I keep understanding things, keep learning from them.

So I am supposed to build a fibered electro-optic modulator and a fibered faraday isolator which can withstand about a 200W laser power. The first experiments will mainly be carried out on the injection of this power in an optic fiber which has to guarantee a good quality of the beam at the output.

I started to think about the equipment that I was needed (specific optic fiber, fiber collimators, very precise translation mechanics) compared to the equipments that we already have in the lab. I made a study to compare the available products on the market to find the ones that match my needs, discussed about it with my supervisor and we bought them.

Then I have made the set up of the experiment, it took time, I had to be very precise and very careful since the power used is very high. Actually for the moment it is still moderate (about 500mW), but I am going to increase it more and more.

Quickly the first problems appeared. The coupling of the free space beam into the fiber is not as easy as I was expecting. The first results on the quality of the fiber are not so bad but we worry about its performance when we will increase the power.

However as one of my colleague told me: “if it was easy and problems free, a thesis would not have been dedicated to it!”. And he is right, it will be my job in the coming weeks to fix these problems and find the good solutions to reach our goal. I am still confident, I will let you know about it!