Abruptly autofocusing property of circular Airy vortex beams with different initial launch angles

Area of Science:

• Optics and Photonics
• Beam Propagation Physics

Background:

• Circular Airy beams (CABs) exhibit unique autofocusing properties.
• Controlling CAB trajectory, particularly with negative launch angles, can diminish autofocusing.

Purpose of the Study:

• To investigate the influence of optical vortex (OV) topological charge on the autofocusing of circular Airy vortex beams (CAVBs) under various launch angles.
• To explore methods for enhancing the abruptly autofocusing property of CABs, especially under negative launch conditions.

Main Methods:

• Numerical simulation of CAVB propagation.
• Analysis of beam trajectory and focal intensity under varying initial launch angles and OV topological charges.

Main Results:

• A higher topological charge of OV enhances the abruptly autofocusing property of CABs, even for negative launch angles.
• Oppositely charged OVs attract and overlap in the focal plane, intensifying autofocusing.
• The autofocusing property diminishes with increasing OV separation, particularly for positive launch angles.

Conclusions:

• The topological charge of OV is a key parameter for controlling and enhancing the autofocusing of CABs.
• OV interaction within CABs offers a mechanism to counteract the reduction in autofocusing caused by negative launch angles.