To generate a photonic nanojet outside a high refractive index microsphere illuminated by a Gaussian beam

Gasparic V, Mayerhoefer TG, Zopf D, Ristic D, Popp J, Ivanda M (2022)

Publication Type: Journal article

Publication year: 2022

Journal

Optics Letters Optical Society of America

Book Volume: 47

Pages Range: 2534-2537

Journal Issue: 10

DOI: 10.1364/OL.459001

Abstract

A non-resonant, concentrated, narrow beam of light emerging from an illuminated microlens is called a photonic nanojet (PNJ). According to currently prevailing opinion, microspheres and microcylinders are only able to generate a PNJ in their exterior when their refractive index ns (or refractive index contrast) is less than 2. In this Letter we demonstrate that a PNJ can emerge from a microsphere even when ns > 2: first by employing the laws of geometrical optics for a divergent light source; then, by using ray transfer matrix analysis, a mathematical condition for the Gaussian beam (GB) outside the high ns microsphere is derived. The PNJ outside the microsphere with ns = 2.5 is simulated using Generalized Lorenz–Mie theory (GLMT), by using a front focused GB source. The simulated difference between front and back focusing on the dependence of ns is confirmed experimentally by Raman imaging. By opening the PNJ field for high refractive index materials, we believe this work will be a nucleus for new ideas in the field and enable new PNJ applications.

Involved external institutions

Rudjer Boskovic Institute (RBI) / Institut Ruđer Bošković (IRB) HR Croatia (HR) Leibniz-Institut für Photonische Technologien e.V. DE Germany (DE)

How to cite

APA:

Gasparic, V., Mayerhoefer, T.G., Zopf, D., Ristic, D., Popp, J., & Ivanda, M. (2022). To generate a photonic nanojet outside a high refractive index microsphere illuminated by a Gaussian beam. Optics Letters, 47(10), 2534-2537. https://dx.doi.org/10.1364/OL.459001

MLA:

Gasparic, Vlatko, et al. "To generate a photonic nanojet outside a high refractive index microsphere illuminated by a Gaussian beam." Optics Letters 47.10 (2022): 2534-2537.

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