The Experts below are selected from a list of 1608 Experts worldwide ranked by ideXlab platform

Jagyeong Kim - One of the best experts on this subject based on the ideXlab platform.

  • selective emitter with engineered anisotropic radiation to minimize dual band thermal signature for infrared Stealth Technology
    ACS Applied Materials & Interfaces, 2020
    Co-Authors: Changhoon Park, Jagyeong Kim, Jae Won Hahn
    Abstract:

    Selective emitters comprising plasmonic resonators have been exploited for cooling devices or infrared Stealth Technology. While selective emitters have been designed using odd-order resonances, even-order resonances also emit anisotropic thermal radiation signals. Thermal radiation by even-order resonances in selective emitters can be experimentally detected by thermal imaging cameras, and such thermal emissions often degrade the observability of infrared detectors, rendering them inapplicable to infrared Stealth Technology. Here, a selective emitter with extremely low thermal radiation signature in a dual-band range, a detection range by an infrared detector, is proposed with engineering anisotropic thermal radiation by even-order resonances. To minimize infrared signature in a dual-band range, the characterization of even-order resonances of gap plasmon metasurfaces is achieved based on vectorial diffraction within a relative error of 10%. Thermal radiation by even-order resonance has been shown to be highly directional and can be experimentally measured using mid-wave infrared images. Based on model prediction, the proposed selective emitter reduces mid-wave infrared signatures and long-wave infrared signatures by factors of 37.95 and 38.06, respectively, compared with those of blackbody surfaces. In addition, numerically confirmed thermal signature reduction and captured mid-wave infrared images indicate excellent thermal camouflage performance of the selective emitter with background medium. Thus, the characterization of even-order resonances provides a basis for the design of metasurfaces that can be employed for multispectral applications, especially infrared Stealth Technology.

  • Selective dual-band metamaterial perfect absorber for infrared Stealth Technology
    Scientific Reports, 2017
    Co-Authors: Jagyeong Kim, Kiwook Han, Jae W. Hahn
    Abstract:

    We propose a dual-band metamaterial perfect absorber with a metal–insulator–metal structure (MIM) for use in infrared (IR) Stealth Technology. We designed the MIM structure to have surface plasmon polariton (SPP) and magnetic polariton (MP) resonance peaks at 1.54 μm and 6.2 μm, respectively. One peak suppresses the scattering signals used by laser-guided missiles, and the other matches the atmospheric absorption band, thereby enabling the suppression of long-wavelength IR (LWIR) and mid-wavelength IR (MWIR) signals from objects as they propagate through the air. We analysed the spectral properties of the resonance peaks by comparing the wavelength of the MP peak calculated using the finite-difference time-domain method with that obtained by utilizing an inductor–capacitor circuit model. We evaluated the dependence of the performance of the dual-band metamaterial perfect absorber on the incident angle of light at the surface. The proposed absorber was able to reduce the scattering of 1.54 μm IR laser light by more than 90% and suppress the MWIR and LWIR signatures by more than 92%, as well as maintain MWIR and LWIR signal reduction rates greater than 90% across a wide temperature range from room temperature to 500 °C.

Jae W. Hahn - One of the best experts on this subject based on the ideXlab platform.

  • Selective dual-band metamaterial perfect absorber for infrared Stealth Technology
    Scientific Reports, 2017
    Co-Authors: Jagyeong Kim, Kiwook Han, Jae W. Hahn
    Abstract:

    We propose a dual-band metamaterial perfect absorber with a metal–insulator–metal structure (MIM) for use in infrared (IR) Stealth Technology. We designed the MIM structure to have surface plasmon polariton (SPP) and magnetic polariton (MP) resonance peaks at 1.54 μm and 6.2 μm, respectively. One peak suppresses the scattering signals used by laser-guided missiles, and the other matches the atmospheric absorption band, thereby enabling the suppression of long-wavelength IR (LWIR) and mid-wavelength IR (MWIR) signals from objects as they propagate through the air. We analysed the spectral properties of the resonance peaks by comparing the wavelength of the MP peak calculated using the finite-difference time-domain method with that obtained by utilizing an inductor–capacitor circuit model. We evaluated the dependence of the performance of the dual-band metamaterial perfect absorber on the incident angle of light at the surface. The proposed absorber was able to reduce the scattering of 1.54 μm IR laser light by more than 90% and suppress the MWIR and LWIR signatures by more than 92%, as well as maintain MWIR and LWIR signal reduction rates greater than 90% across a wide temperature range from room temperature to 500 °C.

Ji Zhou - One of the best experts on this subject based on the ideXlab platform.

  • an extremely broad band metamaterial absorber based on destructive interference
    Optics Express, 2011
    Co-Authors: Jingbo Sun, Lingyun Liu, Guoyan Dong, Ji Zhou
    Abstract:

    We propose a design of an extremely broad frequency band absorber based on destructive interference mechanism. Metamaterial of multilayered SRRs structure is used to realize a desirable refractive index dispersion spectrum, which can induce a successive anti-reflection in a wide frequency range. The corresponding high absorptance originates from the destructive interference of two reflection waves from the two surfaces of the metamaterial. A strongly absorptive bandwidth of almost 60 GHz is demonstrated in the range of 0 to 70 GHz numerically. This design provides an effective and feasible way to construct broad band absorber in Stealth Technology, as well as the enhanced transmittance devices.

  • homogenous isotropic invisible cloak based on geometrical optics
    Optics Express, 2008
    Co-Authors: Jingbo Sun, Ji Zhou, Lei Kang
    Abstract:

    Invisible cloak derived from the coordinate transformation requires its constitutive material to be anisotropic. In this work, we present a cloak of graded-index isotropic material based on the geometrical optics theory. The cloak is realized by concentric multilayered structure with designed refractive index to achieve the low-scattering and smooth power-flow. Full-wave simulations on such a design of a cylindrical cloak are performed to demonstrate the cloaking ability to incident wave of any polarization. Using normal nature material with isotropy and low absorption, the cloak shows light on a practical path to Stealth Technology, especially that in the optical range.

Jingbo Sun - One of the best experts on this subject based on the ideXlab platform.

  • an extremely broad band metamaterial absorber based on destructive interference
    Optics Express, 2011
    Co-Authors: Jingbo Sun, Lingyun Liu, Guoyan Dong, Ji Zhou
    Abstract:

    We propose a design of an extremely broad frequency band absorber based on destructive interference mechanism. Metamaterial of multilayered SRRs structure is used to realize a desirable refractive index dispersion spectrum, which can induce a successive anti-reflection in a wide frequency range. The corresponding high absorptance originates from the destructive interference of two reflection waves from the two surfaces of the metamaterial. A strongly absorptive bandwidth of almost 60 GHz is demonstrated in the range of 0 to 70 GHz numerically. This design provides an effective and feasible way to construct broad band absorber in Stealth Technology, as well as the enhanced transmittance devices.

  • homogenous isotropic invisible cloak based on geometrical optics
    Optics Express, 2008
    Co-Authors: Jingbo Sun, Ji Zhou, Lei Kang
    Abstract:

    Invisible cloak derived from the coordinate transformation requires its constitutive material to be anisotropic. In this work, we present a cloak of graded-index isotropic material based on the geometrical optics theory. The cloak is realized by concentric multilayered structure with designed refractive index to achieve the low-scattering and smooth power-flow. Full-wave simulations on such a design of a cylindrical cloak are performed to demonstrate the cloaking ability to incident wave of any polarization. Using normal nature material with isotropy and low absorption, the cloak shows light on a practical path to Stealth Technology, especially that in the optical range.

Kiwook Han - One of the best experts on this subject based on the ideXlab platform.

  • Selective dual-band metamaterial perfect absorber for infrared Stealth Technology
    Scientific Reports, 2017
    Co-Authors: Jagyeong Kim, Kiwook Han, Jae W. Hahn
    Abstract:

    We propose a dual-band metamaterial perfect absorber with a metal–insulator–metal structure (MIM) for use in infrared (IR) Stealth Technology. We designed the MIM structure to have surface plasmon polariton (SPP) and magnetic polariton (MP) resonance peaks at 1.54 μm and 6.2 μm, respectively. One peak suppresses the scattering signals used by laser-guided missiles, and the other matches the atmospheric absorption band, thereby enabling the suppression of long-wavelength IR (LWIR) and mid-wavelength IR (MWIR) signals from objects as they propagate through the air. We analysed the spectral properties of the resonance peaks by comparing the wavelength of the MP peak calculated using the finite-difference time-domain method with that obtained by utilizing an inductor–capacitor circuit model. We evaluated the dependence of the performance of the dual-band metamaterial perfect absorber on the incident angle of light at the surface. The proposed absorber was able to reduce the scattering of 1.54 μm IR laser light by more than 90% and suppress the MWIR and LWIR signatures by more than 92%, as well as maintain MWIR and LWIR signal reduction rates greater than 90% across a wide temperature range from room temperature to 500 °C.