Ultrahigh Quality Factor Photonic Nanojets Generated by Truncated Microtoroid Structures

Abstract

A photonic nanojet (PNJ) is a highly confined light beam that focuses from the shadow side of microparticles. In 46.47 this work, we propose a PNJ with ultrahigh quality factor formed by dielectric truncated microtoroid. The key properties of PNJ, such as the maximum intensity, the length of PNJ, the full-width at half maximum (FWHM), are studied in detail using finite-difference time-domain (FDTD) analysis. The results show that a PNJ with an enhanced intensity of 55.21 times to the incident light, superlong length of 46.47 and subwavelength FWHM of 0.77 is formed by semi-microtoroid, thus, an ultrahigh quality factor of 3308.68 is achieved. More importantly, the properties of the PNJ are tunable by changing the truncated proportions of the microtoroid. The structure we proposed has the advantages of compact structure and simple experimental operation, which is expected to apply in many research fields, including optical detection, optical data storage, super-resolution image, nanopattern, nanolithography, and so on.

Time domain photonic hook beam for manipulating nanoparticles along curved trajectories

“…Simulations have shown that the greatest beam curvature can be obtained when the remote segment is irradiated near the Brewster angle 30 . Combining key parameters of the photonic hook, and having in mind the quality criteria for the photonic jet 31 , we propose to characterize the PH by a quality criterion Q as…”

Generation of Photonic Nanojet Using Gold Film Dielectric Microdisk Structure

“…Gu et al used liquid-filled microspheres to generate an ultralong PNJ in 2015 [30], Victor Pacheco-Pena et al reported a method of generating PNJs based on the periodic arrangement of a 3D dielectric cuboid micro-structure in 2016 [31], and Geints et al presented a systematic study of the key characteristics (field intensity enhancements, spatial extents) of 2D and 3D photonic nanojets (PNJs) produced by geometrically regular micron-sized dielectric particles illuminated by a plane laser wave in 2018 [32]. Recently, we obtained an ultrahigh-quality factor PNJ Materials 2023, 16, 3146 2 of 12 from truncated microtoroid structures [33], and Xing et al investigated a curved truncated dielectric microcylinder structure using the finite element method, which can form an ultralong PNJ with the longest effective length, in 2022 [34].…”