Ultrahigh Quality Factor Photonic Nanojets Generated by Truncated Microtoroid Structures

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.

Automated summary

In this study, a photonic nanojet (PNJ) with ultrahigh quality factor formed by dielectric truncated microtoroid is proposed. The key properties of the PNJ, such as maximum intensity, length, and full-width at half maximum (FWHM), are analyzed in depth using finite-difference time-domain (FDTD) analysis. The PNJ with an enhanced intensity, superlong length, and subwavelength FWHM is formed by a semi-microtoroid, achieving an ultrahigh quality factor that is tunable by changing the truncated proportions of the microtoroid. The compact structure and simple experimental operation make it promising for applications in various research fields.