Bessel beam scanning for microscopy and lithography applications

Arabelle Margaret Ocampo^1*, Wynn Dunn Gil Improso¹, Giovanni A. Tapang¹

¹Physics, National Institute of Physics, Quezon City, Manila, Philippines

* Presenter:Arabelle Margaret Ocampo, email:aocampo@nip.upd.edu.ph

We investigate Bessel beams generated and controlled using holographic methods. Utilizing a phase-only spatial light modulator (SLM), we dynamically control Bessel beams, shaping them from an input phase hologram based on the axicon's opening angle. Control is done by phase modifications: linear phase shifts enable lateral translations (x and y directions) through a grating phase addition, and axial translations (z-direction) are achieved by incorporating a quadratic chirp phase derived from the Fresnel diffraction algorithm. Our scanning technique allows us to observe Bessel beams at various distances, revealing their remarkable resistance to diffractive spreading across a 2.2 mm Fourier space. This extended depth of focus suggests their potential in microscopy and lithography. We also examine Bessel beams at 0.3x and 1.2x magnifications.

Keywords: Optical system design, Fourier Optics, Optical modulator