Read me file: University of Southampton – ORC – Huaiqin Lin – hl3g15@soton.ac.uk The excel file contains experimental data for the paper. In particular: Fig. 2.(a) Laser output power versus absorbed pump power. Inset: Laser output spectrum at 110 W output. Resolution: 0.5 nm. Fig. 2.(b) Temporal power characteristic Fig. 2.(c) Measured beam radius of the output signal in the horizontal and vertical beam axes at maximum output power. Date of data collection: from November 2017 - January 2018 Information about geographic location of data collection: University of Southampton, U.K. Date that the file was created: January 2018