Multispectral Optical Confusion System: Visible to Infrared Coloration with Fractal Nanostructures

Optical confusion refers to a camouflage technique assimilated with the surroundings through manipulating colors and patterns. With the advances in multispectral imagery detection systems, multispectral camouflage studies on simultaneous deceptions in the visible to infrared ranges remain a key challenge. Thus, creating pixelated patterns is essential for mimicking background signatures by assimilating both colors and patterns. In this study, a multispectral optical confusion system (MOCS) comprising pixelated silicon-based fractal nanostructures (Si-FNSs) is introduced to realize multispectral optical confusion. We analyzed the fractality of the Si-FNSs to understand the relationships between structural characteristics and optical properties with the aggregation phenomenon. The aggregation phenomenon changes the morphological heterogeneity by up to 38.5%, enabling a controllable range of visible reflectivity from 0.01 to 0.12 and infrared emissivity from 0.33 to 0.90. Visible and infrared colors were obtained by controlling the wet-etching time from 10 to 240 min and temperature from 40 to 100 degrees C. Finally, the MOCS consisting of pixelated Si-FNSs was designed and created by extracting the pattern from the simultaneously captured visible and infrared background images. Using the artificial backgrounds representing these images, we evaluated and compared the multispectral optical confusion performance of the MOCS with conventional camouflage surfaces.

Automated summary

This study introduces a multispectral optical confusion system (MOCS) composed of pixelated silicon-based fractal nanostructures (Si-FNSs) to achieve multispectral optical confusion by assimilating colors and patterns. The morphological heterogeneity of Si-FNSs can be changed to control the visible reflectivity and infrared emissivity within certain ranges. The MOCS is designed and created by extracting patterns from simultaneously captured visible and infrared background images. Compared to conventional camouflage surfaces, the MOCS shows superior multispectral optical confusion performance.