Design of Wavelength-Selective Surfaces for Mid-Infrared Detectors Using Heavily Doped Silicon Complex Gratings

Author(s):  
Y.-B. Chen ◽  
Z. M. Zhang

The feasibility of using complex gratings for mid-infrared wavelength-selective absorbers is investigated. Nano/microscale surface features are employed for tailoring thermal radiative properties, which are much different from those of plain surfaces. High absorptance from heavily doped ( > 1×1020 cm−3) silicon for the transverse magnetic wave incidence can be achieved with one-dimensional periodic gratings by exciting surface plasmon polaritons. For simple binary gratings, the associated absorptance peak is narrowband and directional sensitive. These drawbacks can be remedied by using complex gratings, whose features are a superposition of multiple simple surface-relief gratings. The spectral absorptance displays a peak whose full-width-at-half-maximum (FWHM) exceeds 1.5 μm and is less sensitive to the angle of incidence. Moreover, the peak wavelength can be adjusted by varying the doping concentration and grating geometry. This study demonstrates that the use of complex gratings may significantly enhance the performance of infrared detectors.

Author(s):  
Jiao Chi ◽  
Hongjun Liu ◽  
Zhaolu Wang ◽  
Nan Huang

Abstract Graphene plasmons with enhanced localized electric field have been used for boosting the light-matter interaction in linear optical nano-devices. Meanwhile, graphene is an excellent nonlinear material for several third-order nonlinear processes. We present a theoretical investigation of the mechanism of plasmon-enhanced third-order nonlinearity susceptibility of graphene nanoribbons. It is demonstrated that the third-order nonlinearity susceptibility of graphene nanoribbons with excited graphene surface plasmon polaritons can be an order of magnitude larger than the intrinsic susceptibility of a continuous graphene sheet. Combining these properties with the relaxed phase matching condition due to the ultrathin graphene, we propose a novel plasmon-enhanced mid-infrared wavelength converter with arrays of graphene nanoribbons. The wavelength of sig-nal light is in mid-infrared range, which can excite the tunable surface plasmon polaritons in arrays of graphene nanoribbons. The efficiency of the converter from mid-infrared to near-infrared wavelength can be remarkably improved by 60 times compared with the graphene sheet without graphene plasmons. This work provides a novel idea for the efficient application of graphene in the nonlinear optical nano-devices. The proposed mid-infrared wavelength converter is compact, tunable and has promising potential in graphene-based mid-infrared detector with high detection efficiency.


Author(s):  
Y.-B. Chen ◽  
J.-S. Chen ◽  
P.-F. Hsu

Radiative properties (absorptance, reflectance, and transmittance) of deep slits with five nanoscale slit profile variations at the transverse magnetic wave incidence are numerically investigated in this work by employing the rigorous coupled-wave analysis. For slits with attached features, their radiative properties can be much different due to the modified cavity geometry and dangled structures, even at wavelengths between 3 and 15 μm. The shifts of cavity resonance excitation result in higher transmittance through narrower slits at specific wavelengths and resonance modes are confirmed with the electromagnetic fields. Opposite roles possibly played by features in increasing or decreasing absorptance are determined by the feature position and demonstrated by Poynting vectors. Correlations among all properties of a representative slit array, the angle of incidence, and the slit density are also comprehensively studied.


2019 ◽  
Vol 33 (20) ◽  
pp. 1950219 ◽  
Author(s):  
Chittaranjan Nayak ◽  
Alireza Aghajamali ◽  
Ardhendu Saha ◽  
Narottam Das

By using the transfer matrix method, the theoretical investigation has been carried out in the near- and mid-infrared bandgaps for a periodic multilayered structure that was composed of superconductor (SC) and semiconductor-metamaterial. It was found that two bandgaps appeared within the computational regions which are effectively optimized by manipulating the thickness of the SC film, fill factor of the semiconductor-metamaterial and the incidence angle of the incident electromagnetic wave. However, the thickness of the SC film and fill factor of the semiconductor-metamaterial are responsible for the red-shift of bandgaps, while the blue-shift is accounted for by the angle of incidence for both transverse electric (TE) and transverse magnetic (TM) waves. It is notable, for the TM wave, that the bandgaps disappeared at the incident angles of approximately 60[Formula: see text]. Such properties are quite useful in designing any new types of edge filters and other optical devices in the near- and mid-infrared frequencies.


2016 ◽  
Vol 12 (2) ◽  
pp. 4278-4290
Author(s):  
Faouzi Ghmari ◽  
Ilhem Mezni

The purpose of this paper is to study the radiative properties of two model structures. The first model (A-1) is a rectangular grating of silicon (Si). The second one (A-2) is obtained from A-1 by filling their trenches by SiO2. These patterned wafers are characterized by three geometrical parameters, the period d, the filling factorand the thickness h. To derive and compute the radiative properties we use a rigorous coupled wave analysis (RCWA) method. Our attention is focused on the absorptance of these structures when they are illuminated by a monochromatic plane wave. We investigate the effect of the filling factor on the absorptance versus the direction of the incident wave. At specific angles of incidence the effect of the period is also studied. Besides, the influence of the thickness h on the absorptance is included throughout this work. At the wavelength = 632,8nm, we especially show that we can identify several perfect absorber model structures characterized by specific parameters and by accurate angle of incidence. We show that this will be done in both transverse electric (TE) and transverse magnetic (TM) polarization cases.


Author(s):  
Ai-Hua Wang ◽  
Pei-feng Hsu ◽  
Yu-Bin Chen ◽  
Lin-Hua Liu

Based on the prior work by authors, radiative properties of modified complex gratings with nanoscale features are studied. The purpose of this work is to demonstrate, even preliminary, the possibility of using complex gratings and nanoscale surface features to modify far field radiative properties. A finite-difference time-domain numerical scheme was used to model the infrared radiative properties of heavily doped silicon simple and complex gratings. The solutions were validated with those of rigorous coupled-wave analysis method. By properly choosing the carrier concentration and geometry, silicon complex gratings exhibit a broadband absorptance peak resulting from the excitation of surface plasmon polaritons. Meanwhile, the absorptance of four modified complex gratings with attached features has been numerically investigated for the impacts of the attached structures. Firstly, though absorptance spectra of gratings almost remain unchanged, their locations shift towards longer wavelengths. Secondly, the spectral absorptance peak of two modified complex gratings is wider than that of gratings without attached features due to the cavity resonance excitation. Thirdly, the spectral absorptance of complex gratings with square features in three sizes was compared and shows that the peak wavelength shifts toward longer wavelengths with enlarged feature size.


2019 ◽  
Vol 514 ◽  
pp. 36-39 ◽  
Author(s):  
P. Srisinsuphya ◽  
K. Rongrueangkul ◽  
R. Khanchaitham ◽  
S. Thainoi ◽  
S. Kiravittaya ◽  
...  

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Evgeny D. Filippov ◽  
Sergey S. Makarov ◽  
Konstantin F. Burdonov ◽  
Weipeng Yao ◽  
Guilhem Revet ◽  
...  

AbstractWe analyze, using experiments and 3D MHD numerical simulations, the dynamic and radiative properties of a plasma ablated by a laser (1 ns, 10$$^{12}$$ 12 –10$$^{13}$$ 13 W/cm$$^2$$ 2 ) from a solid target as it expands into a homogeneous, strong magnetic field (up to 30 T) that is transverse to its main expansion axis. We find that as early as 2 ns after the start of the expansion, the plasma becomes constrained by the magnetic field. As the magnetic field strength is increased, more plasma is confined close to the target and is heated by magnetic compression. We also observe that after $$\sim 8$$ ∼ 8  ns, the plasma is being overall shaped in a slab, with the plasma being compressed perpendicularly to the magnetic field, and being extended along the magnetic field direction. This dense slab rapidly expands into vacuum; however, it contains only $$\sim 2\%$$ ∼ 2 % of the total plasma. As a result of the higher density and increased heating of the plasma confined against the laser-irradiated solid target, there is a net enhancement of the total X-ray emissivity induced by the magnetization.


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