Coloured vortex beams with incoherent white light illumination

Area of Science:

• Optics and Photonics
• Nanotechnology

Background:

• Orbital angular momentum (OAM) is crucial for high-capacity optical applications.
• Generating OAM beams typically requires spatio-temporally coherent light sources like lasers.
• Incoherent light usually results in smeared or obscured OAM beam features.

Purpose of the Study:

• To demonstrate the generation of colored orbital angular momentum (OAM) beams using incoherent white light.
• To overcome the limitations of using coherent light sources for OAM beam generation.
• To develop novel optical elements for advanced anti-counterfeiting and photonic lock-key applications.

Main Methods:

• Miniaturized spiral phase plates were developed.
• These plates were integrated with nanoscale structural color filters using 3D nanoprinting.
• The combined elements achieve spatio-temporal coherence for OAM beam generation from incoherent light.

Main Results:

• Successfully generated colored OAM beams using incoherent white light.
• Demonstrated the ability to independently control color and OAM information.
• Developed 3D optical elements encoding both color and OAM information.

Conclusions:

• The developed method enables the generation of OAM beams from readily available incoherent white light.
• The integrated optical elements significantly increase the combinatorial possibilities for optical security applications.
• This approach offers a novel pathway for advanced photonic devices by combining color and OAM functionalities.