Investigation of Stray Radiation Suppression in Infrared Imaging System Using a Novel Broadband and High-Absorption Ceramic Coating

Abstract

Aiming at addressing the vulnerability of the infrared imaging opto-mechanical system to stray radiation interference caused by an external laser, a new method with a broadband and high-absorptivity ceramic coating on the inner wall of the system is proposed to reduce the stray radiation intensity, which is helpful to improve the imaging quality of the detection image. Based on plasma electrolytic oxidation (PEO) technology, the preparation method and properties of a novel ceramic coating are studied, and a long-wave infrared imaging optical system with high-absorption ceramic coating is designed and developed. It is verified for the first time that the high-absorption ceramic coating can suppress the stray radiation in the infrared opto-mechanical system, and the effect of laser incident power and angle on the stray radiation is investigated. The experimental results show that the ceramic coating can achieve 95.4% high absorption in the wavelength range of 0.2–16 μm, which can obviously suppress the stray radiation in the opto-mechanical system of infrared imaging caused by laser. The calculation of the stray radiation suppression ratio shows that, compared with the case without coating, the stray radiation intensity in the system can be reduced by 70% using the ceramic coating.

The Effect of Heat Treatment on the Structural-Phase State and Abrasive Wear Resistance of a Hard-Anodized Layer on Aluminum Alloy 1011

“…The use of carcinogenic and environmentally harmful electrolytes in the implementation of the chromium plating method makes it environmentally hazardous [1,13,14]. PEO is used to form oxide layers on compact aluminum alloys [15][16][17], to oxidize aluminum coatings deposited in various ways on a steel base [18][19][20][21][22], or on other substrates [23,24]. PEO of aluminum alloys makes it possible to obtain surface layers with high hardness (up to 2000 HV), low friction coefficient, high adhesion to the metal base, and low environmental hazard [25][26][27][28].…”

Abrasive Wear Resistance and Tribological Characteristics of Pulsed Hard Anodized Layers on Aluminum Alloy 1011 in Tribocontact with Steel and Ceramics in Various Lubricants

“…In particular, chromium plating provides high hardness (up to 1000 HV) and corrosion resistance of the surface layer, but for its implementation, carcinogenic and environmentally harmful electrolytes are used, which do not comply with the REACH regulations [1,2,14,15]. The PEO method is used to harden the surface layers both on aluminum alloys [2,16,17] and on aluminum coatings deposited in various ways on steel [18][19][20][21][22] or other [23,24] substrates. PEO layers on aluminum alloys have high hardness (up to 2000 HV), adhesion to the substrate, and a low friction coefficient [25][26][27][28][29].…”

Hybrid Electromagnetic Signal Feature Extraction

“…They believe that the polarization characteristic parameters are mainly reflected in the complex amplitude of the scattering center, independent of the frequency, and azimuth dependence of the target [16]. The attribute scattering center model proposed in 1997 continued this idea, thinking that the target changes with frequency and angle under each polarization channel are the same, and the complex amplitude under each polarization channel is different with different polarization modes [17]. In 2013, Peng-Peng et al also proposed a theoretical model of coherent polarization diffraction of the target to describe the dispersion and polarization characteristics of the target scattering center and gave the corresponding feature extraction algorithm [18].…”