Design and optimization of diamond-shaped biosensor using photonic crystal nano-ring resonator

In this paper, we present a diamond-shaped biosensor based on the nano-ring resonator using two-dimensional photonic crystal (2D-PhC). The biosensor is consisted of a ring resonator and two waveguides. The ring resonator with two end waveguides on both sides, are placed in the middle of structure. Due to the analyte binding to the sensing hole, the refractive index of hole is changed and consequently the resonant wavelength is shifted. According to the results, the resonant wavelength shift in the range of 1.33–1.54 is linearly proportional to the refractive index variations. The quality factor and the sensitivity of biosensor are respectively obtained about 3700 and 3.4 nm/fg. The minimum detectable biomolecule weight in a sensing hole for a diamond-shaped nano-ring resonator is derived as 0.029 fg.