Wavelength selective uncooled infrared sensor by plasmonics

Abstract

A wavelength selective uncooled infrared (IR) sensor using two-dimensional plasmonic crystals (2D PLCs) has been developed. The numerical investigation of 2D PLCs demonstrates that the wavelength of absorption can be mainly controlled by the period of the surface structure. A microelectromechanical systems-based uncooled IR sensor with 2D PLCs as the IR absorber was fabricated through a complementary metal oxide semiconductor and a micromachining technique. The selective enhancement of responsivity was observed at the wavelength that coincided with the period of the 2D-PLC absorber.

Enhancing the Responsivity of Uncooled Infrared Detectors Using Plasmonics for High-Performance Infrared Spectroscopy

“…In addition, adding the plasmonic crystal structure reduces the responsivity of the IR detector at other wavelengths. This shows that the gold plasmonic crystal structure does function not only as an absorber, but also as an optical filter as reported in [3]. The IR absorption spectrum of methane at a concentration of 30,000 parts-per-million (ppm) (Fig 5(b)) is obtained using the fabricated IR detector in the range of 1400 cm -1 to 1200 cm -1 with a spectral resolution of 1 cm-1 (7.14 µm to 8.33 µm in wavelength) to show multiple absorption peaks in this spectral range.…”

“…When the IR radiation is selectively absorbed by the plasmonic crystal structure, the temperature of the IR detector increases which results in a voltage change between top and bottom platinum electrodes. There are four parameters that define the dimensions of the plasmonic crystal structure: the array pitch p, the gold layer thickness t, the hole radius r, and the hole depth d. The combination of these parameters determines the wavelength at which SPPs are excited and IR absorption is enhanced [3]. Finite element simulations are performed using commercially available software, COMSOL TM RF Module, to optimize the dimensions of the plasmonic crystal structure for maximum absorption around the wavelength λ = 7.7 µm which has multiple characteristic IR absorption peaks of methane [23].…”

“…Although the significant losses associated with their propagation hindered their wide use for many applications [16,17], they can be exploited to enhance the performance of IR detectors by enhancing the absorption of IR radiation. Thus, SPPs have been recently employed to enhance the responsivity of IR detectors [3,18,19,20].…”

Absorption Properties of Simply Fabricated All-Metal Mushroom Plasmonic Metamaterials Incorporating Tube-Shaped Posts for Multi-Color Uncooled Infrared Image Sensor Applications

“…Figure 2a summarizes the calculated absorbance results. These data indicate that the absorption wavelength can be controlled by varying the micropatch width, and the absorption wavelength can be longer than the micropatch period, which can lead to smaller pixel size compared with twodimensional plasmonic absorbers [10,11]. It is evident that this device exhibits wavelength-selective The absorption properties of the MPMAT were quantitatively assessed using rigorous coupled wave analysis (RCWA), fixing the values of p, t m , h, and t b at 6.0 µm, 100 nm, 200 nm, and 100 nm, Photonics 2016, 3, 9 3 of 8 respectively.…”

“…Plasmonic metamaterial absorbers are structurally scalable, which enables a wide range of applications at various wavelengths, including solar cells in the visible range [6], biological sensors in the near infrared (IR) [7] and middle IR [8], and thermal sensors in the IR [9][10][11][12] and terahertz ranges [13,14], as well as EW shielding [15] and wireless microwave transfer [16]. Wavelength-selective IR absorbers show significant promise as advanced uncooled IR sensors since they allow the identification of objects through their radiation spectra [17], and many applications of these devices are anticipated, such as in gas analysis, fire detection, multi-color imaging [18], and hazardous materials recognition [19].…”