Semiconductor Physics, Quantum Electronics & Optoelectronics. 2014. V. 17, N 1. P. 100-105.
Extraordinary high-Q resonances in the scattering
by a dielectric slab containing a grating of circular cylinders
1Institute of Radio-Physics and Electronics NAS of Ukraine, Laboratory of Micro and Nano Optics,
61085 Kharkiv, Ukraine
Abstract. An infinite dielectric wire grating in free space is known to possess very high- Q resonances at the frequencies close to the Rayleigh anomalies. Still a practical implementation of such a resonator may require its embedding in a dielectric slab. In this paper, it is shown that this can bring additional improvement of the Q-factors. A dielectric slab with a symmetrically embedded dielectric-wire grating is investigated under the normal incidence of plane waves. Accurate numerical solutions are derived for the E- and H-polarization cases. Associated eigenvalue problems are solved for the real- valued lasing frequencies and the threshold values of material gain.
Keywords: grating, sub-wavelength wires, reflection resonances, lasing thresholds.
Manuscript received 11.10.13; revised version received 15.01.14; accepted for publication 20.03.14; published online 31.03.14.