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.