Search Results - "Sensors"

Wearable strain sensors have transformed the real‐time monitoring of health conditions and human–machine interactions. However, recently developed wearable strain sensors exhibit several limitations. For example, when a sensor is designed with high sensitivity to detect strain, it struggles to accur...

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Sensitive detection of heavy metals, organic dyes, and microorganisms in water is essential for sustaining human safety. Here, optical and electrochemical comprehensive sensing approaches and techniques for diagnosis and pollutant identification have been investigated. Biosensors are a primary tool...

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The development of materials science, artificial intelligence and wearable technology has created both opportunities and challenges for the next generation of bionic sensor technology. Bionic sensors are extensively utilized in the collection and monitoring of human biological signals. Human biologi...

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DM is a chronic metabolic disorder characterized by insufficient insulin production or impaired use in the cells, leading to a high blood glucose level. This disease requires constant monitoring of blood glucose levels. Traditional blood glucose monitoring techniques are invasive and inconvenient, h...

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In the context of the relentless pursuit of precision, intelligence, and personalization within the realm of medical technology, the real-time monitoring of human physiological signals has assumed heightened significance. Implantable wireless sensor devices have exhibited extraordinary capabilities...

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We experimentally investigated the performance of a distributed acoustic sensor (DAS) designed using a few-mode fiber (FMF), when launching different spatial modes under intentional index perturbation within the fiber. Our demonstration showed that the quasi-single mode (QSM) operated FMF offers hig...

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Abstract Wireless, passive, and flexible strain sensors can transform structural health monitoring across various applications by eliminating the need for wired connections and active power sources. Such sensors offer the dual benefits of operational simplicity and high‐function adaptability. Herein...

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A flexible and stable optical fiber sensor based on the Sagnac loop is proposed and experimentally demonstrated for the measurement of salinity and temperature, simultaneously. The sensing unit consists of a tapered polarization maintaining fiber (tPMF) and a fiber Bragg grating (FBG) connected in s...

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We propose a refractive index (RI) and temperature sensor design based on hybrid mechanisms in a D-shaped all-solid photonic crystal fiber. The D-shaped flat surface is coated with a silver film to construct surface plasmon resonance for the RI sensing, while a single hole in the all-solid structure...

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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. Afterward...

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We propose a temperature insensitive optical fiber Fabry–Perot (FP) sensor for liquid level measurement. The sensor is based on a silicon diaphragm and borosilicate glass ferrules. Through the combination of different ferrules, the FP cavity is fabricated without a seal to eliminate the i...

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Distributed fiber-optic vibration sensors based on phase-sensitive optical time-domain reflectometry ( <inline-formula> <tex-math notation="LaTeX">$\phi$</tex-math></inline-formula>-OTDR) have found many applications in various fields. In this paper, we analyze the...

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A novel fiber-optic liquid level sensor based on a cross-correlation optical time-domain Fresnel reflection technology is proposed and demonstrated. By processing a single-mode fiber (SMF) to create multiple gaps for generating Fresnel reflections, liquids surrounding the SMF modify Fresnel reflecti...

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The industrial production system for broiler chickens involves raising the animals in an artificial environment (aviary) that must provide all necessary conditions to generate a suitable microclimate. This microclimate ensures optimal development of the animals based on their productive indices and...

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Many satellites use closed-loop attitude control to carry out their missions. They use several sensors such as sun, magnetometer, and star tracker to close the control loop. Sun sensors are not operational during the eclipse and therefore, one of the observed vectors is lost.  For this reason, attit...

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A sensitivity analysis of absorption sensing based on the symmetrical metal-cladding waveguide is presented. The calculated reflectivity curve shows that any minute variation of the extinction coefficient due to absorption of the sample will easily give rise to a dramatic change in the minimum refle...

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We propose a novel long-period grating (LPG) based on a ring-core hollow fiber (RCHF) filled with functional liquid as a tunable material. The RCHF structure is simple. The effective refractive index tuning characteristics of the liquid-filled RCHF-LPG are investigated. The RCHF-LPG functions as a t...

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A Silicon waveguide incorporating a vertical slot filled with Al^&#x002B;3 doped ZnO is proposed for gas sensing. The effect of different device parameters, namely, slot-height, slot-width, and Si-width on two key optical features related to sensing, that is, difference in...

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In this paper, we propose a new scheme of refractive index (RI) sensing, which utilizes frequency-sensitive responses of 2-D photonic crystals. Specifically, the 2-D photonics crystals consist of dielectric rods arranged in rectangular lattice and support frequency-sensitive supercollimation (SC). S...

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