Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7925639 | Optics Communications | 2018 | 6 Pages |
Abstract
Photonic nanojets (PNJs) owing to their sub-wavelength near-field features have found many interesting applications like nanoscopy, nano photolithography, high density optical storage, enhancement of Raman signal and single molecule spectroscopy etc. More recently, the focus of research has been on tailoring of PNJs either for better confinement and thus higher peak intensity or for elongation of nanojet for high resolution far field applications. In this paper, we show that crescent-shape refractive index profile (CSRP) of microspheres can be used to generate highly confined PNJ. By optimizing the refractive index of different layers in CSRP microsphere, we show a free space confinement down to â¼Î»â4.5 (FWHM â¼110 nm for excitation with 500 nm wavelength). Further, it was observed that the optical properties of substrates also modulate the PNJ characteristics and lead to a further improvement in the transverse confinement toâ¼Î»â6.7.
Keywords
Related Topics
Physical Sciences and Engineering
Materials Science
Electronic, Optical and Magnetic Materials
Authors
H.S. Patel, P.K. Kushwaha, M.K. Swami,