Implementation of laser speckle analysis for designing effective graded microwave absorbers

Abstract Laser speckle analysis is a highly sensitive, non-destructive optical technique that plays a crucial role in material surface analysis, particularly for designing of effective graded microwave absorber. Unique inherent features of laser speckle facilitates to characterize the surface and structural properties of any polymer blended fiber reinforced decorated with graphene nanoplatelets. The technique provides detailed insights into critical parameters such as surface roughness and micro structural uniformity essential for optimizing electromagnetic absorption and shielding performance. By enabling precise surface characterization, laser speckle analysis facilitates the tailored design of the composite’s graded architecture to achieve impedance matching and enhance microwave absorption. Experimental results reveal a strong correlation between laser speckle metrics with the surface roughness which influences the different microwave absorption properties such as reduced reflection coefficient approaching towards threshold reflection coefficient −20 dB over X-band frequency range. The speckle contrast reflects the surface texture of nanofiller material has perturbed surface enabling the high absorption followed by skin depth demonstrating superior performance as microwave absorber. This study underscores the indispensable role of laser speckle analysis in advancing efficient, lightweight, and sustainable microwave absorber as shielding material for aerospace, stealth, and communication technologies.