Core Viewpoint - The article discusses the development of advanced stealth materials using photonic crystals, highlighting the innovative research and engineering efforts of a team led by Professor Shi Jiaming at the National University of Defense Technology, aimed at enhancing military equipment's stealth capabilities against various detection methods [1][2][3]. Group 1: Research and Development - The need for improved stealth protection for military equipment has become urgent due to advancements in electronic reconnaissance and precision-guided technologies [2]. - The research began with the exploration of photonic crystals, which can manipulate electromagnetic waves by adjusting their optical properties, although they were initially only in the experimental stage [2][3]. - The team successfully developed a theoretical model to block specific frequency electromagnetic waves by designing the periodic structure of photonic crystals [2][3]. Group 2: Engineering and Testing - The team progressed to the engineering phase, creating small samples of photonic crystals and testing their effectiveness on silicon substrates, which showed promising results [4]. - However, challenges arose when transitioning to flexible fabric substrates, leading to extensive trials and adjustments to the manufacturing process [5][6]. - After three years of dedicated efforts, the team overcame significant technical hurdles to enable the large-scale production of flexible photonic crystal films [6][7]. Group 3: Multi-band Detection Solutions - The team faced new challenges in achieving infrared stealth for high-temperature targets while also addressing laser and radar detection, which required different approaches [7]. - A novel concept called "spectral hole drilling" was developed to create specific transmission channels within the photonic crystal structure, allowing for effective stealth across multiple detection bands [7][8]. - Successful tests demonstrated that the stealth materials did not compromise the performance of the radar systems while effectively evading detection [8]. Group 4: Future Directions - The team continues to optimize their processes and technologies, with a focus on rapid innovation and adaptation to enhance combat capabilities [8]. - The emphasis on developing new quality combat power aligns with national directives to leverage advanced technologies for military applications [8].