Fig. 4: Visualization and quantitative analysis of transparent gas flow.

a, b Single-shot acquisition of the horizontal and vertical dimensions of the gas flow field: (a) CO₂ jet field, (b) He jet field. The purple dashed box indicates the position of the gas outlet. c, d Light deflection caused by density variations in the flow field, with (c) corresponding to the CO₂ jet field, and (d) corresponding to the He jet field. d₁ and d₂ represent the distances from the gas emission port to the measured flow field. The ‘+’ and ‘-’ symbols represent light deflection to the left (up) and right (down), respectively. e-f Radial density distribution of CO₂ (e) and He (f) at a position 5 mm from the gas outlet