Max Planck Institute for Nuclear Physics - Harshank Shrotriya

Temporal characterization of Attosecond pulses.

Max Planck Institute for Nuclear Physics (MPIK), Heidelberg, Germany.

Work

I joined the Quantum Dynamics and Control division at MPIK for 10 weeks for my summer internship. Ultrafast optics is useful in studying processes in nature which happen on a very small time scale. With the discovery of High Harmonic Generation it is possible to generate ultrashort Laser pulses with attosecond duration. But these pulses are of no use if they are not characterized before using them to observe other phenomenon (like observing Photoionization time delay). My work dealt with characterizing an attosecond time scale pulse in time domain so as to identify the intensity, phase variation and length (FWHM) of the pulse.

For the first few weeks I read about algorithms used to characterize these pulses and discussed them with other PhD students in the group. I was assigned one particular PhD student whom I had already been corresponding with 2 months before going there and we used to meet regularly for any discussion required.

After understanding the theory I implemented the algorithms using Python. The way an ultrashort Laser pulse is measured experimentally is through a Frequency Resolved Optical Gating (FROG) spectrogram. I visited the lab a few times but my work didn’t require any experimental knowledge.

Pulse compression part of the Laser setup.

Getting the internship

I had already done some work in this field during my SLP at the start of 3rd year and my SLP supervisor suggested some places where I could apply for an internship. After going through their work I sent mails to them describing the work I had already done and how I can contribute to their current research. Once I got a positive response from MPIK, I also requested for any funding available and by some arrangement for international visitor fund at MPIK I got a sufficient stipend to live there for 10 weeks. Accommodation was provided at MPIK’s guest house itself, the charges of which were deducted from my stipend.

VISA

It is beneficial to apply for the VISA as soon as you get the acceptance letter and work permit from the institute. If you are applying through German embassy then the work permit is very necessary to get the VISA as it is the proof that you will get some sort of funding from the institute and would be able to survive there. However I am not sure the work permit is necessary for people going through DAAD scholarship. I got the VISA about 4 weeks after submitting the documents at the VISA office.  

General

Heidelberg is a small town along the river Neckar and a good tourist destination. The institute is situated in the hills and a little far from the main market place. Buses are available to and from the institute every hour however the ticket fare is expensive. For those interested in tourism, I would recommend to take a credit card which is required to make bookings everywhere. Canteens and coffee shops are situated near the campus but a better and cheaper option would be to cook your own meal once everyday. A fully furnished kitchen was available inside the guest house. Transport is the most expensive service while common grocery items and raw food is cheaper compared to India.