<p>This paper compares the performance of axicon phase modulation and Bessel phase modulation in generating perfect optical vortices (POVs). Theoretical analysis and experimental verification show that the POVs generated by axicon phase modulation have energy concentrated on the ring, but the ring radius varies with changes in topological charge. The POVs generated by Bessel phase modulation have side lobes in addition to the main ring, but most of the energy is still focused on the main ring, and the ring radius is relatively stable. Suggestions for generating POVs in different scenarios are provided in the paper.</p>