White Vortex Light Generations With 7OCB Spherulite

TL;DR

Researchers used 7OCB spherulites to generate optical vortex beams with unique properties across a wide range of light wavelengths.

Contribution

A new method for generating broadband optical vortex beams using 7OCB spherulites is introduced.

Findings

7OCB spherulites enable polychromatic optical vortex beams from visible to near-infrared wavelengths.

Noncoherent white light optical vortex beams can be generated via spin-to-orbital angular momentum conversion.

The spherulites show high contrast in polarized transmittance, making them efficient for structured light generation.

Abstract

A spherulite is a radially symmetric, microscale crystalline aggregate formed by molecular self‐assembly, typically exhibiting concentric birefringent textures under polarized light, which is highly sought after for optical applications, especially in structured light generation and modulation. In this work, we exploit the optical properties of spherulites formed by 7OCB molecules. Radially aggregated needle‐like 7OCB crystals result in a strong anisotropic transmittance with respect to radial and azimuthal orientations due to scattering loss over a wide range. Thus, polychromatic generation of cylindrical vector optical vortex beams across a broad spectrum from visible to near infrared, as well as a noncoherent white light optical vortex beam, is realized via spin‐to‐orbital angular momentum conversion from the spherulite. This approach opens promising opportunities for employing spherulites in structured‐light generation and in the modulation of both polarization and angular momentum.

A spherulite made of radially arranged needle‐like 7OCB crystals exhibits a high contrast regarding polarized transmittance along radial and azimuthal directions across the entire visible range. Thus, it can function as an efficient generator of broadband polychromatic optical vortices, as well as a noncoherent white light vortex beam.

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