Liquid-crystal adaptive equivalent q-plate device with tunable topological charge.

Area of Science:

• Optics and Photonics
• Materials Science

Background:

• Cylindrical vector beams (CVBs) are crucial for advanced optical applications.
• Existing methods for generating CVBs with tunable topological charges are often complex or lack dynamic control.

Purpose of the Study:

• To present a proof-of-concept for a novel liquid-crystal device capable of generating tunable cylindrical vector beams (CVBs).
• To demonstrate dynamic control over the topological charge of generated CVBs.

Main Methods:

• The device combines two adaptive spiral phase plates (ASPPs) and a quarter-wave plate (QWP).
• ASPPs utilize circular transmission electrodes with radial lines to impart spiral phases.
• Addressing specific voltages allows independent control over polarization states and topological charges.

Main Results:

• The device efficiently generates arbitrary CVBs, including pure and hybrid states.
• Topological charges can be dynamically tuned by adjusting four voltages.
• Performance analysis maps device behavior onto Poincaré and higher-order Poincaré spheres.
• The device functions as a tunable q-plate, termed adaptive q-plate (AQ-plate).

Conclusions:

• The developed AQ-plate offers a versatile and dynamically controllable method for generating CVBs.
• This novel device provides an advantage over traditional q-plates with its dynamic tunability.
• Experimental results validate the device's versatility for various optical applications.