1. School of Physics and Astronomy, Queen Mary University of London, Mile End, London E1 4NS, United Kingdom
2. ISIS, STFC Rutherford Appleton Laboratory, Didcot OX11 0QX, United Kingdom
3. College of Physical Science and Technology, Sichuan University, Chengdu, 610064, People’s Republic of China
4. Litron Lasers Ltd., Rugby CV21 1PB, United Kingdom
5. School of Biological and Chemical Sciences, Queen Mary University of London, Mile End, London E1 4NS, United Kingdom