Photonic Bandgaps in Disordered Inverse‐Opal Photonic Crystals

Three‐dimensional photonic crystals with full bandgaps at optical wavelengths can be fabricated with inverse‐opal techniques. We have shown that the bandgap is extremely sensitive to the presence of geometric disorder in the crystals (see Figure). The bandgap closes completely with a disorder strength as small as under two percent of the lattice constant. This fragility persists even at very high refractive index contrasts and is attributed to the creation of a bandgap at high frequency bands (8–9 bands) in inverse‐opal crystals. This should impose severe demand on the quality of lattice uniformity.     

Silicon Inverse Opal—A Platform for Photonic Bandgap Research

This article focuses attention on recent research on the silicon inverse opal, the first self‐assembled or bottom–up synthetic photonic crystal to exhibit a complete photonic bandgap (PBG) at 1.5 μm^[1] in accordance with theoretical predictions.^[2] The silicon inverse opal has since proven to be a useful platform for assembling on‐chip films^[3] and in‐chip patterns,^[4] engineering extrinsic defects,^[5] mapping photon density of states,^[6] switching light with light, and inhibiting spontaneous emission.^[7] Also, new and exciting colloidal‐crystal‐based structures are being developed based on experimental and theoretical knowledge acquired for the synthesis of inverted silicon photonic crystals.^[8–10] It has also inspired the idea of the silicon inverse opal heterostructure, a theoretical construct that could enable an all‐optical microchip for single mode diffractionless waveguiding of light in air throughout a bandwidth of more than 70 nm at 1.5 μm.^[11]     

低光泽度热隐身光子晶体薄膜

为了降低热隐身薄膜在可见光探测下的显著性,研究了低光泽度热隐身光子晶体薄膜的设计和制备问题。首先分析了影响光子晶体热隐身薄膜光泽度的因素,然后从基底的粗糙度,可见光波段平均反射率,以及合适的镀膜工艺三个方面进行优化,按照优化方案进行制备和测试分析,最终得到低光泽度热隐身光子晶体薄膜。结果显示,所研制的光子晶体薄膜的光泽度可以减小到4.2个光泽单位左右,符合相关标准。并且在中、远红外大气窗口内的波段发射率分别为0.20和0.25,说明该低光泽度薄膜对中远红外具有较强的隐身性能。