Optical Sensors for Industrial and Biomedical Applications

Document Type : Research Article

Authors

1 School of ECE, College of Engineering, University of Tehran

2 School of Electrical Engineering, Iran University of Science and Technology

Abstract

The article begins with a brief review of those industrial and biomedical optical sensors which have been designed and fabricated in Photonics Research Laboratory, School of Electrical and Computer Engineering, University of Tehran. Firstly, development of a fiber-based fluid temperature and pressure sensing system is described. We describe fabrication procedure for the designed temperature and pressure sensors and elaborate on the interrogating electronic system for processing the sensor signals. Then, a frequency-modulation interferometric sensor enabling low-cost and highly sensitive refractive index measurement is presented. The sensor utilizes a setup based on free-space optics. Having introduced the first categories of sensors, we briefly describe transmission-line formulation (TLF) method which has been developed in our research group for the diffraction analysis of optical periodic structures. Application of this method to the design of a coupled cross-stacked guided-mode resonance sensor with a high surface sensitivity is demonstrated. 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.

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