One- and two-dimensional ring array formed by birefringence in tandem with conical refraction: experimental...

Area of Science:

• Optics and Photonics
• Laser Physics
• Materials Science

Background:

• Birefringent (BR) crystals and conical refraction (CR) phenomena are key to advanced beam shaping.
• Previous work established theoretical frameworks for forming ring beam arrays using cascaded BR and CR crystals.
• Controlling light polarization and crystal orientation is crucial for manipulating beam patterns.

Purpose of the Study:

• To experimentally validate the formation of tunable ring beam arrays using cascaded birefringent and conical refraction crystals.
• To investigate the transformation of CR ring arrays into different configurations (parallelogram, linear, rectangular).
• To demonstrate the agreement between numerical simulations and experimental results for optical ring array generation.

Main Methods:

• Numerical simulation of circularly polarized Gaussian beam propagation through two BR crystals (m=2) and a CR crystal.
• Experimental setup utilizing cascaded YVO4 (BR) and KGW (CR) crystals.
• Adjustment of crystal orientations and half-wave plate rotation to control array geometry.

Main Results:

• A parallelogram array of four CR rings was successfully formed at the focal plane.
• The parallelogram array was controllably transformed into linear and rectangular CR ring arrays.
• Experimental observations closely matched the predictions from theoretical simulations.

Conclusions:

• The experimental study confirms the feasibility of generating tunable CR ring arrays using cascaded BR and CR crystals.
• The demonstrated method offers precise control over the geometry of optical ring arrays.
• This work advances the understanding and application of beam shaping techniques in optics.