Low refractive index materials have always gained attention for avoiding optical losses in numerous devices like Light emitting diodes (LEDs), Distributed Bragg Reflectors (DBRs) etc. Glancing angle deposition (GLAD) has proven to be an effective method for depositing porous nanostructures with low refractive index. SiO₂ has the lowest refractive index in comparison to most of the materials present in nature and is therefore utilized extensively in the fabrication of optical devices with minimum optical losses. The present work focuses on the SiO₂ nanostructured thin films grown using glancing angle (GLAD) configuration in RF Sputtering technique under varying deposition conditions (glancing angle and pressure) at fixed thickness. The deposited porous SiO₂ nanostructured layers have well-defined nanorods of feature size smaller than 100 nm. The refractive index corresponding to all the deposited SiO₂ nanostructured films came out to be smaller than the corresponding value (1.49) mentioned in the literature for bulk SiO2. The refractive index has been observed to vary in a wide range (1.05 to 1.40). Characterization of the deposited SiO₂ nanostructured films was carried out using Fourier Transform Infrared (FTIR) spectroscopy, Energy Dispersive X-Ray (EDS) analysis, and Atomic Force Microscopy (AFM) to assess the qualitative properties of the deposited nanostructured SiO₂ films. Surface Plasmon Resonance (SPR) and Ellipsometry studies are performed to determine the refractive index value of the deposited nanostructured SiO₂ thin films. A refractive index value as low as ∼ 1.05 at a wavelength of 633 nm is achieved for SiO₂ nanostructured thin film deposited at 30 mTorr deposition pressure and 80° glancing angle.

低折射率材料一直备受关注，可避免发光二极管(LED)、分布式布拉格反射器(DBR) 等众多器件中的光学损耗。掠角沉积 (GLAD) 已被证明是一种沉积多孔纳米结构的有效方法，具有低折射率。与自然界中存在的大多数材料相比， SiO ₂具有最低的折射率，因此广泛用于制造光学损耗最小的光学器件。目前的工作重点是使用掠射角 (GLAD) 配置生长的 SiO ₂纳米结构薄膜固定厚度下不同沉积条件（掠射角和压力）下的射频溅射技术。沉积的多孔 SiO ₂纳米结构层具有特征尺寸小于 100 nm 的明确定义的纳米棒。_{对应于所有沉积的SiO 2纳米结构膜}的折射率结果小于文献中提到的块体SiO2 的相应值(1.49)。已观察到折射率在很宽的范围内变化（1.05 至 1.40）。_{使用傅里叶变换红外(} FTIR ) 光谱、能量色散 X 射线(EDS) 分析和原子力显微镜 (AFM) 以评估沉积的纳米结构 SiO ₂薄膜的定性特性。进行表面等离子共振(SPR) 和椭圆偏振研究以确定沉积的纳米结构化 SiO ₂薄膜的折射率值。_{对于在 30 mTorr 沉积压力和 80° 掠射角下沉积的 SiO 2}纳米结构薄膜，在 633 nm 波长处实现低至 1.05 的折射率值。