Guided-mode resonance sensors: different schemes for different applications

Abstract

This work performs a quantitative comparison of different dielectric-based guided-mode resonance (D-GMR) sensors. To this end, diverse D-GMR structures are classified into three different classes, and their sensitivity (S) is compared to each other. For one of these classes in various schemes, the sensitivity is investigated for the TE and TM modes. Moreover, grating height effects are studied for different cases in this category, and analytical sensitivity equations are used as benchmarks. Then, the three classes are compared and, based on the numerical results and analytical equations, various applications are proposed for different structures in the refractive index (RI) of interest. Comparing our results to other recent works, we prove that the proposed classification leads to great sensing performances and the predictions are reliable. A comparison has been performed for methane as a gas sample (with RI of 1.0003) and a hemoglobin solution and toluene as two different analytes (with RIs of 1.33 and 1.4778, respectively). The results show a sensitivity of S = 1427.3 n m / r e f r a c t i v e index unit (nm/RIU) for methane with a detection precision of one to a few volume percentages in the air, which can also be calibrated to illuminate the fabrication variation errors. For hemoglobin, a sensitivity of 1073.4 nm/RIU is obtained, with a limit of detection of 116.15 mg/lit for 65-87 g/lit of hemoglobin in water; for the toluene sensor, S = 1019.7 n m / R I U is calculated. As a general result, a high figure of merit/sensitivity can be achieved over a wide range of applications, from gases to high RI analytes, using our proposed classifications.