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arXiv · 2103.17179

Structured light engineering using a photonic nanojet

Maryam Yousefi·Daniel Necesal·Toralf Scharf·Markus Rossi
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Abstract

In this letter, we present the photonic nanojet as a phenomenon in a structured light generator system that is implemented to modify the source focal spot size and emission angle. The optical system comprises a microlens array that is illuminated by a focused Gaussian beam to generate a structured pattern in the far-field. By introducing a spheroid with different aspect ratios in the focus of the Gaussian beam, the source optical characteristics change and a photonic nanojet is generated which will engineer the far-field distribution. To probe the light fields we implement a high-resolution interferometry setup to extract both the phase and intensity at different planes. We both numerically and experimentally demonstrate that the pattern distribution in the far-field can be engineered by photonic nanojet. As an example, we examine prolate, sphere, and ablate geometries. An interesting finding is that depending on the spheroid geometry, a smaller transverse FWHM of a photonic nanojet with a higher diverges angle produces an increased pattern field of view at the same physical size of the optical system.

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Maryam Yousefi, Daniel Necesal, Toralf Scharf, Markus Rossi. 2021-03-31. Structured light engineering using a photonic nanojet. https://doi.org/10.1364/ol.425121

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