Electrically switchable optical vortex generated by a computer-generated hologram recorded in polymer-dispersed...

Area of Science:

• Optics and Photonics
• Materials Science

Background:

• Optical vortices are beams of light with a helical phase front, finding applications in areas like optical trapping and microscopy.
• Controlling and generating optical vortices efficiently, especially with dynamic switching capabilities, remains an active area of research.

Purpose of the Study:

• To develop a computer-generated hologram for generating optical vortices using polymer-dispersed liquid crystal (PDLC) material.
• To investigate the reconstruction fidelity and diffraction efficiency of the generated optical vortex.
• To explore the possibility of electrically switching the reconstructed optical vortex beam.

Main Methods:

• A computer-generated hologram was recorded in a PDLC cell using a 514.5 nm Ar+ laser.
• Photopolymerization-induced phase separation created index modulation within the PDLC.
• Reconstruction of the optical vortex was achieved using a collimated He-Ne laser beam.

Main Results:

• High-fidelity reconstruction of an optical vortex beam was successfully demonstrated.
• The diffraction efficiency of the reconstructed beam was measured to be between 13% and 17%.
• Applying a suitable voltage allowed for the switching of the reconstructed optical vortex beam.

Conclusions:

• PDLCs are a viable medium for recording computer-generated holograms to produce optical vortices.
• The developed holographic element exhibits good reconstruction fidelity and efficiency.
• The electrical tunability of PDLCs enables dynamic control and switching of optical vortex beams.