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Journal ArticleDOI

Design of a Terahertz Alcohol Sensor Using a Steering-Wheel Microstructured Photonic Crystal Fiber

25 Aug 2020-Iete Journal of Research (Taylor & Francis)-pp 1-9

AbstractIn this paper, we design a novel photonic crystal fiber (PCF) chemical sensor wherein the cladding structure is made of a steering-wheel (SW)-shaped large non-circular air-hole. In this PCF, we int... more

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Journal ArticleDOI
Abstract: We report the first use of pulsed terahertz spectroscopy to examine low-frequency collective vibrational modes of biomolecules. Broadband absorption increasing with frequency was observed for lyophilized powder samples of calf thymus DNA, bovine serum albumin and collagen in the 0.06–2.00 THz (2–67 cm−1) frequency range, suggesting that a large number of the low-frequency collective modes for these systems are IR active. Transmission measurements at room temperature showed increasing FIR absorption with hydration and denaturing.

635 citations

Journal ArticleDOI
Abstract: We report on a promising approach for the label-free analysis of DNA molecules using direct probing of the binding state of DNA with electromagnetic waves at THz frequencies. Passive THz resonator devices based on planar waveguides are used as sample carriers and transducers for THz transmission analysis. In comparison to a formerly used free-space detection scheme, this method provides a drastically enhanced sensitivity enabling analysis down to femtomol levels. We examine the potential of our approach on biologically relevant DNA samples and demonstrate the detection of single base mutations on DNA molecules.

474 citations

Journal ArticleDOI
Abstract: We report broad bandwidth, 0.1–10 THz time-domain spectroscopy of linear and electro-optic polymers. The common THz optical component materials high-density polyethylene, polytetrafluoroethylene, polyimide (Kapton), and polyethylene cyclic olefin copolymer (Topas) were evaluated for broadband THz applications. Host polymers polymethyl methacrylate, polystyrene, and two types of amorphous polycarbonate were also examined for suitability as host for several important chromophores in guest-host electro-optic polymer composites for use as broadband THz emitters and sensors.

313 citations

Journal ArticleDOI
Abstract: In this paper, we present an overview of chemical recognition with ultrashort THz pulses. We describe the experimental technique and demonstrate how signals for chemical recognition of substances in sealed containers can be obtained, based on the broadband absorption spectra of the substances. We then discuss chemical recognition in combination with THz imaging and show that certain groups of biological substances may give rise to characteristic recognition signals. Finally, we explore the power of numerical prediction of absorption spectra of molecular crystals and illuminate some of the challenges facing state-of-the-art computational chemistry software.

253 citations

Journal ArticleDOI
TL;DR: A review of photonic crystal fiber sensors is presented; two different groups of sensors are detailed separately: physical and biochemical sensors, based on the sensor measured parameter.
Abstract: Photonic crystal fibers are a kind of fiber optics that present a diversity of new and improved features beyond what conventional optical fibers can offer. Due to their unique geometric structure, photonic crystal fibers present special properties and capabilities that lead to an outstanding potential for sensing applications. A review of photonic crystal fiber sensors is presented. Two different groups of sensors are detailed separately: physical and biochemical sensors, based on the sensor measured parameter. Several sensors have been reported until the date, and more are expected to be developed due to the remarkable characteristics such fibers can offer.

209 citations