Analysis and design of optical biosensors using one-dimensional photonic crystals

作者：Singh Ankit; Thapa Khem B^*; Kumar Narendra

来源：Optik, 2015, 126(2): 244-250.

DOI：10.1016/j.ijleo.2014.08.172

• Optical biosensors
• Sensitivity
• Field intensity

An analysis and design of an optical biosensor is presented considering a one-dimensional photonic crystal, which is in form of periodic dielectric media. In order to study the properties of 1D PC in terms of reflectance (R), transmittance (7), field intensity and sensitivity; we have employed the transfer matrix method (TMM). A design of the optical biosensors is thus proposed by considering the 1D PC structure like S/(HL)(N)/S having two different materials of high H and low L refractive indices, respectively, and S represents the substrate. In 1D PC, there exists a defect layer X, breaking the periodic structure as S/H(LH)(N/2)/X/(HL)H-N/2/S, and a defect state (resonance mode) will appear at a certain position in the band gap. In our work, we have made theoretical analysis of a perfect optical biosensor using the 1D PC based on label-free optical sensing, which does not use fluorescence based-detection, where porous silicon interacts with biomolecule and reduces its refractive index by biomolecular reaction. The designed sensor identifies the molecule on the basis of two parameters with the change in the characteristic peaks in the obtained curves, that are, the electric field intensity and sensitivity with varying the total thickness of the material. This analysis can be useful to design an optical sensor with 1D PC and to evaluate the performance of biosensors in terms of high sensitivity, resolution or detection limit.

• 出版日期2015