An On‐Chip Quad‐Wavelength Pyroelectric Sensor for Spectroscopic Infrared Sensing

Abstract

Merging photonic structures and optoelectronic sensors into a single chip may yield a sensor‐on‐chip spectroscopic device that can measure the spectrum of matter. In this work, an on‐chip concurrent multiwavelength infrared (IR) sensor, which consists of a set of narrowband wavelength‐selective plasmonic perfect absorbers combined with pyroelectric sensors, where the response of each pyroelectric sensor is boosted only at the resonance of the nanostructured absorber, is proposed and realized. The proposed absorber, which is based on Wood's anomaly absorption from a 2D plasmonic square lattice, shows a narrowband polarization‐independent resonance (quality factor – Q of 73) with a nearly perfect absorptivity as high as 0.99 at normal incidence. The fabricated quad‐wavelength IR sensors exhibit four different narrowband spectral responses at normal incidence following the predesigned resonances in the mid‐wavelength infrared region that corresponds to the atmospheric window. The device can be applied for practical spectroscopic applications such as nondispersive IR sensors, IR chemical imaging devices, pyrometers, and spectroscopic thermography imaging.

MEMS-Based Wavelength-Selective Bolometers

“…The angle-resolved absorptivity was also simulated, and the result is summarized in Figure 1d. Although there exists another resonance in the shorter wavelength region which is attributed to the surface plasmon polariton (SPP) at Au/air interface of the periodic Au square lattice array [38,39], the main resonance (magnetic mode) remains unchanged up to 70° incidence. This large working angle of the proposed device is essential for the practical applications.…”

“…The resonance of the absorber is so-called magnetic resonance. Interestingly, due to the optical loss of the metal, the absorbed energy at the resonance arises at the top Au resonator and bottom Au film subsequently converts to heat through Joule heating that follows Poynting’s theorem [38,40]. The resonantly generated heat is then conductively transferred to the bolometer film via a thin Si 3 N 4 layer to trigger the change of the electrical resistance for IR sensing.…”

“…The dielectric functions of Au, Ti, Si, SiO 2 and Al 2 O 3 were taken from literatures [36,37]. The dielectric function of Si 3 N 4 was from the reference [38]. For the FDTD simulations, periodic boundary conditions were applied to both the x - and y -directions and perfectly matched layers were applied to the z -axis.…”

Metallic cavity quantum well infrared photodetector for filter-free SF6 gas imaging

“…All these additional components require the necessary space for installation, and also require additional cooling power to reduce their own infrared radiation, which is especially critical for gas detection in the long-wavelength infrared band. Though several micro-filters (Lu et al 2009;Li et al 2016) which could be integrated with the sensor pixel have been developed (this is considered to be the key point to miniaturization of imaging systems), such as the Fabry-Pérot filter (Neumann et al 2008;Frey et al 2015;Mao et al 2016;Xu et al 2017) and the plasmonic filter (Genet and Ebbesen 2007;Liang et al 2017;Wang and Dan 2018;Dao et al 2019;Xu et al 2019), most of their bandwidths are still broad at infrared band, approximately 1 μm around 10.6 um wavelength.…”

High-performance Tunable Multichannel Absorbers Couple with Graphene-based Grating and Dual-Tamm Plasmonic Structures

“…Graphene monolayer thickness determined at tg=0.34 nm with its dielectric permittivity εg=1+iσg/(ωε0tg), where σg is the surface conductivity of graphene and ε0 is the vacuum dielectric constant, ω is the angular frequency of the incident wave. The conductivity is highly dependent on the chemical potential μc, which is determined at 0.3eV in this work taking into account the data[32,33]. The upper spectrum in Fig.3(b)shows the absorptance when the resonance mode is excited by the TM…”