Generation of a Purely Single Transverse Mode Vortex Beam from a He-Ne Laser Cavity with a Spot-Defect Mirror

<table>A cross-section of the intensity distribution of the beam for <i>d</i> = 50 <i>μ</i>m. Dotted lines and a red solid curve indicate the measured data and fitting result, respectively.</table>

International Journal of Optics

fig4

Figure 4

Figure 4: Generation of a Purely Single Transverse Mode Vortex Beam from a He-Ne Laser Cavity with a Spot-Defect Mirror 