Colorful radiative coolers (CRCs) can be widely applied for energy sustainability especially and meet aesthetic purposes simultaneously. Here, we propose a high-efficiency CRC based on thin film stacks and engineered diffuse reflection unit, which brings out 7.1 °C temperature difference compared with ambient under ~ 700 W·m-2 solar irradiation. Different from analogous schemes, the proposed CRCs produce vivid colors by diffuse reflection and rest of the incident light is specular-reflected without being absorbed. Adopting the structure of TiO2/SiO2 multilayer stack, the nanophotonic radiative cooler shows extra low absorption across the solar radiation waveband. Significant radiative cooling performance can be achieved with the emissivity reaching 95.6% in the atmosphere transparent window (8–13 μm). Moreover, such CRC can be fabricated on flexible substrates, facilitating various applications such as the thermal management of cars or wearables. In conclusion, this work demonstrates a new approach for color display with negligible solar radiation absorption and paves the way for prominent radiative cooling.

采用原子层沉积(ALD)技术在石英管表面制备了薄膜,研究了该薄膜的均匀性,以及石英管的内径、外径、长度对沉积薄膜均匀性的影响。以单波长减反射膜为研究对象,实验测试的反射光谱与仿真结果一致,石英管表面最低反射率可降至0.17%。忽略夹具影响,石英管外壁与内壁的减反射薄膜的非均匀性基本一致,在±1.69%范围内,内外壁表面减反射薄膜的厚度和中心波长相同,且石英管尺寸对内外壁薄膜均匀性无明显影响。利用ALD技术可在大曲率元件的内外表面沉积厚度偏差小且均匀性分布相似的减反射薄膜。

研究了离子束溅射(IBS)制备的Nb₂O₅、Ta₂O₅和SiO₂薄膜的光学特性、力学特性以及薄膜微结构,分析了辅助离子源电压对薄膜特性的影响,并将电子束蒸发、离子辅助沉积和IBS制备的薄膜进行了对比。研究结果表明,IBS制备的薄膜具有更好的光学特性和微结构,同时具有较大的压应力、硬度和杨氏模量;辅助离子源可以改善薄膜的光学特性,调节薄膜应力和减小薄膜表面粗糙度,但对硬度和杨氏模量的影响相对较小。在不同的辅助离子源电压下,IBS制备的Nb₂O₅应力为-152~-281 MPa, Ta₂O₅的应力为-299~-373 MPa,SiO₂的应力为-427~-577 MPa;在合适的工艺参数下,消光系数可小于10 ^-4;薄膜表面平整,均方根粗糙度小于0.2 nm。

设计和制备了一种用于1064 nm分振幅光偏振测量仪(DOAP)的具有多层介质薄膜结构的差分相移分束镜。通过理论分析该DOAP系统的仪器矩阵参数, 得到分束镜的最优参数, 并用离子束溅射沉积方法制备了分束镜样品及其背面的减反射膜, 其实测结果与设计值吻合较好。与单层薄膜分束镜相比, 多层介质薄膜分束镜不受基板、膜层材料, 以及入射角和工作波长的限制, 具有更广泛的应用。

以乙酰丙酮铱[Ir(acac)3]和高纯氧为前驱体，采用原子层沉积(ALD)方法在基板温度为340 ℃的石英玻璃和硅基板上制备了金属铱薄膜。采用反射光谱测试仪、X射线电子能谱（XPS）、X射线衍射（XRD）、扫描电子显微镜(SEM)和原子力显微镜(AFM)等手段对不同厚度薄膜的微结构、表面形貌和光学性能进行了研究。结果表明，原子层沉积制备的Ir薄膜中元素纯度较高（大于95%），表面粗糙度低，并呈现多晶纳米颗粒。同时，Ir薄膜在紫外波段表现出较好的光学特性，可以用于制作Ir金属紫外光栅等光学器件。

A scanning white-light interferometer is built for precisely measuring phase properties of dispersive multilayer thin film structure with the aid of the commercial spectrometer. Combining seeking optimal function for interferogram maximas with wavelet denoising algorithm, a novel time-domain algorithm is presented which enables the direct extraction of group delay and thus obtains a remarkable decrease of noise level in group delay and group delay dispersion. The apparatus shows reasonable potential for multilayer measurement, material characterization, displacement measurement as well as profilometry.

Trimethylamine (TMA), TiCl4, and water are applied as the precursors to deposit Al2O3 and TiO2. With different substrate temperatures, the optical properties and surface morphologies of the two oxides TiO2 and SiO2 are studied, respectively. With substrate temperature of 120 oC, amorphous TiO2 can be obtained, and the surface roughness (RMS) is only 0.928 nm. Applying Al2O3 and TiO2 deposited in 120 oC as low and high refractive index materials, anti-reflection (AR) coating at single point (550 nm) is designed. Furthermore, with the calibrated growth rates, this AR coating is fabricated, and its ultimate reflectance for the AR coating at 550 nm is less than 0.2%, which can meet the requirement for most applications.

为精确测量超快激光色散补偿薄膜的群延迟色散，提出了一种基于窗口傅里叶变换和样条插值去噪算法的新型白光干涉测量方案。计算机模拟表明此方法测试精度可达0.58 fs2。分析了高斯噪声和光强平均效应对测试精度的影响，并使用此方法对实验制备的Gires-Tournois干涉反射镜和啁啾镜进行了测试，在宽光谱范围内测试误差小于10 fs2。该方法相比其他算法可以更快速、更精确地实现薄膜相位信息的提取，具有更高的测试精度和实用性。

基于诱导反射原理设计了一种可见光波段金属介质薄膜结构的反射型彩色滤光片。高吸收铬和高反射铝的应用使它既能获得高反射率又有很高的宽波段截止度，通过改变介质匹配层的厚度实现适当的导纳匹配，得到了反射率大于72%、较高色饱和度的红绿蓝三色滤光片。实验制作了样品，测试结果与设计相吻合。基于半色调技术，采用光刻和剥离工艺制备了不同面积占空比的滤光片阵列，实现了高分辨率、介于红绿蓝三色之间中间色的光学反射单元。

以乙醇钽[Ta(OC2H5)5]和水蒸气为前驱体，采用原子层沉积（ALD）方法分别在基板温度为250 ℃和300 ℃的K9和石英衬底上制备了Ta2O5光学薄膜。采用分光光度计、X射线光电子能谱（XPS）、X射线衍射（XRD）、扫描电子显微镜（SEM）和原子力显微镜（AFM）等手段对薄膜的光学特性、微结构和表面形貌进行了研究。结果表明，用ALD方法制备的Ta2O5薄膜在刚沉积和350 ℃退火后均为无定形结构，而250 ℃温度下沉积的薄膜其表面粗糙度低，聚集密度很高，光学均匀性优，在中紫外到近红外均表现出很好的光学特性，可以作为高折射率材料很好地应用于光学薄膜中。