Figure 3

(a) Comparison of refractive index changing with temperature, for experiments with continuous irradiation of various microwave power. The irradiation time is changed to provide a consistent 4000 J overall. (b) The minimum refractive index measured for each run, showing a greater decrease in refractive index with higher irradiation power. (c) Refractive index measured with different salt solutions. Each solution was made up to 0.1 M and irradiated with 200 W for 20 s. For (a,c), markers show the average RI at 1 °C intervals, with the error bars indicating the range of the measured data. (d) RI data as a function of temperature during cooling after irradiation of 4000 J at 20 W, 40 W and 800 W. Reference data for the RI of water is from Mitra et al.¹².