Figure 6

Axicon interference patterns for different values of the applied amplitude A: (a) 0.8, (b) 1.4, (c) 1.8, and (d) 2 V. A 1 V offset is also introduced at the low frequency harmonic of 1 Hz.

Axicon interference patterns for different values of the applied amplitude A: (a) 0.8, (b) 1.4, (c) 1.8, and (d) 2 V. A 1 V offset is also introduced at the low frequency harmonic of 1 Hz.