Figure 3 : Complex amplitude modulation concept.

From: A digital laser for on-demand laser modes

Figure 3

(a) Schematic of the complex plane showing two phase-only values, A and B, lies on the unit circle (unit amplitude). The average of these is vector C, representing amplitude modulation as it is not on the unit circle. (b) Example of a checkerboard pattern of the two phase values A and B. (c) Zoomed out image of b showing the complete annular ring created with this checkerboard pattern to result in zero transmission in the annular ring.