Optical Sensors for Industrial and Biomedical Applications

This article begins with a brief review of those industrial and biomedical optical sensors which have been designed and fabricated in Photonics Research Laboratory at the University of Tehran. Firstly, development of a fiber-based fluid temperature and pressure sensing system is described. Afterwards, a frequency-modulation interferometric sensor enabling low-cost and highly sensitive refractive index measurement is presented. Having introduced these categories of sensors, we briefly describe the Transmission-Line Formulation (TLF) method which has been developed for the diffraction analysis of optical periodic structures. The application of this method is demonstrated to the design of a coupled cross-stacked Guided-Mode Resonance sensor with a high surface sensitivity.  We further review the design of dual-resonance nanostructured plasmonic sensors that can be used to differentiate background refractive index variation from adsorption of a layer on the sensing surface, and to estimate the thickness of adsorbed layers.  Finally, we use the TLF method to design a spectrometer-free configuration for a dual-mode plasmonic sensor, which substantially simplifies the measurement setup.