Bessel beam generating apparatus and method thereof

A method for generating Bessel beams, comprising the steps of:

• utilizing a light source to generate an incident beam to a phase modulation module;
• utilizing the phase modulation module to rectify the incident beam into a circular beam, and to modulate a phase of the circular beam into an asymmetric phase so as to form an asymmetric collimated circular beam provided to a scanning module;
• utilizing the scanning module to compensate the asymmetric collimated circular beam, and utilizing the asymmetric collimated circular beam to scan at different angles and then enter a focusing element, wherein the scanning module is a dual-axis scanning module having a first scanning lens and a second scanning lens;
• and
• utilizing the focusing element to focus and interfere the asymmetric collimated circular beam to form a Bessel beam for machining;
• wherein the phase modulation module includes:
• a conical lens configured to rectify the incident beam into a diverse circular beam;
• and
• a collimation element configured to modulate the diverse circular beam into a collimated circular beam.