(Raw Data Set) High Q/V single-mode nanobeam-grating resonator, functional in the ultra-high sensitive label-free lab-on-a-chip chemical sensor

Abstract

In this paper, we design and optimize a single-mode photonic crystal (PhC) nanobeam-grating (NBG) structure with antisymmetric quarter-elliptical walls geometry based on the computational finite element method (FEM). This structure is capable of providing a wide bandwidth spectrum for chemical sensing (ChS) operation due to the 2 triangle lambda approximate to 110 nm wide bandgap (with a Bragg wavelength center of lambda B approximate to 1550 nm) and filtering out the undesired optical modes. Due to the ChS mode intensification (fundamental mode TE1 wavelength lambda = 1550 nm) with a high quality (Q) factor Q = 3.565 x 103 and a very small modal volume (MVol) Vmode = 0.0012(lambda res/nSi)3 in the cavity area as well as confinement of the evanescent wave mode (EWM) in the air grating near the cavity (where chemical analyte, ChAn, is placed) supporting a very high confinement factor (CFac), Gamma approximate to 0.45, the single-mode PhC nanobeam resonator offers a very good platform for ChS operation with very low light dissipation. The proposed nanobeam photonic resonator structure can analyze a very small surface analyte, 0.01199 mu m2 of ChAn such as ethanol (C2H5OH) and water (H2O) with extremely high sensitivities SEthanol approximate to 1554.22 nm/RIU and SWater approximate to 1549.49 nm/RIU, respectively. The high sensitivity S and high Q/Vmode ratio, the capability of Label-Free sensing operation as well as being ultra-compact, indicate that the single-mode nanobeam structure as a passive photonic structure is a very practical candidate in the Lab-on-a-Chip (LOC) chemical sensor systems.