The Mid-Infrared Photonic Crystals for Gas Sensing Applications

Abstract

Mid-infrared spectrum is known as the "molecular fingerprint" region, where most of the trace gases have their identical absorption patterns. Photonic crystals allow the control of light-matter interactions within micro/nanoscales, offering unique advantages for gas analyzing applications. Therefore, investigating mid-infrared photonic crystal based gas sensing methods is of significant importance for the gas sensing systems with high sensitivity and portable footprint features. In recent various photonic crystal gas sensing techniques have been developing rapidly in the mid-infrared region. They operate either by detecting the optical spectrum behavior or by measuring the material properties, such as the gas absorption patterns, the refractive index, as well as the electrical conductivities. Here, we will brief the progress, and review the above-listed photonic crystal approaches in the mid-infrared range. Their uniqueness and weakness will both be presented. Although the technical level for them has not been ready for commercialization yet, their small size, weight, power consumption and cost (SWaP-C) features offer great values and indicate their enormous application potentials in future, especially under the stimulation of the newly emerging technology "Internet of Things" which heavily relies on modern SWaP-C sensor devices.

Bragg reflector one-dimensional multi-layer structure sensor for the detection of thyroid cancer cells

“…For the proposed design, mid-infrared wavelength of 10.6 μm incident light is considered. Because of good molecular fingerprints in the mid-infrared region, it offers higher sensitivity of the sensor [24], [25]. The obtained geometrical thickness for low and high index layer is 1.21 μm and 0.6625 μm respectively.…”

Ultra-high sensitive 2D photonic crystal for gas and chemical sensing applications

“…For example, monitoring the toxic gases such as NO2, CO2, CO and O3 is of pivotal importance owing to the severity of their harmful effects on the human communities [1]. There are several approaches for gas sensing including semiconductor [2], catalytic [3], electrochemical [4], and optical gas sensors [5] [6]. The optical gas sensors are considered as one of the most promising approaches due its high reliability as a fast, precise, long life expectancy and fitted to the Lab on chip applications (LOC) [7].…”

Experimental study of the size-dependent photoluminescence emission of CBD-grown PbSe nanocrystals on glass

“…Therefore, photoluminescence emissions of lead chalcogenides NCs can cover the near-infrared region entirely, and specifically lead selenide (PbSe) NCs cover PL emissions over the mid-infrared wavelengths [11,12]. Efficient mid-infrared devices play an essential role in a variety of applications, including remote detection, environmental sensing, and gas analysis [13][14][15].…”