Generation of a quasi-Bessel beam with a super-Gaussian axial intensity profile

We report a simple method to generate a quasi-Bessel beam (QBB) with a super-Gaussian (SG) axial intensity profile and reduced intensity oscillations. The axial intensity oscillations of a QBB with a flat-top axial intensity profile produced by a diffractive axicon phase are theoretically analyzed, showing that unwanted intensity oscillations can be significantly mitigated by setting an axial intensity profile to a high-order SG function with optimized parameters. This approach was experimentally applied to generate a QBB with a 12th-order SG axial intensity profile using a spatial light modulator, confirming good agreement with theoretical predictions.