Papers by Keyword: Optical Applications

Abstract: We report on the development and systematic validation of an ultra-pure silicon carbide (SiC) source material specifically engineered for physical vapor transport (PVT) growth of optical-and electronic-grade single crystals. The material is synthesized by chemical vapor deposition (CVD) using high-purity chlorosilane and methane precursors, yielding dense, void-free polycrystalline 3C-SiC with precise 1:1 stoichiometry. Over more than two years of continuous production, bulk metallic impurities across 17 monitored elements were consistently maintained below 100 parts per billion by weight (ppbw), with most batches achieving <50 ppbw. Surface metals, assessed after proprietary crushing and cleaning processes, were similarly controlled to <100 ppbw. Nitrogen levels, determined by secondary ion mass spectrometry (SIMS), remained stable in the low 10¹⁵ cm⁻³ range, enabling semi-insulating or precisely doped crystal growth. Purity and reproducibility were verified by a cross-technique analytical approach including glow discharge mass spectrometry (GDMS), and inductively coupled plasma mass spectrometry (ICP-MS). Microstructural investigations confirmed dense, void-free grains and high crystallographic uniformity. With production capacity scaling toward 60 tons per month, this CVD-based SiC source material establishes a robust platform for next-generation PVT growth. Its combination of ultra-low contamination, structural integrity, and scalable manufacturing positions it as a key enabler for optical SiC applications such as transparent wafers for augmented reality (AR) systems, as well as advanced power and RF devices.

Abstract: Diamond-Like Carbon (DLC) films were deposited on quartz substrates by using a gas mixture of hydrogen-methane-oxygen in the Star-Shape Microwave Plasma enhanced Chemical Vapor Deposition (MPCVD) reactor. The pretreatment parameters include the pretreatment methods and the pretreatment time was optimized. Results showed that ultrasonically abrasive in the acetone solution with nanocrystalline diamond powder in it was an efficient pretreatment method to advance the deposition of DLC films, and 10 minute turned to be the most appropriate time for this pretreatment. The Fourier Transform Infrared spectrometer (FTIR) showed that the DLC films synthesized by the optimized technics have high transparence fit for optical applications. These indicated that the Star-Shape MPCVD reactor was the perfect equipment for the volume-produce of DLC films for its unique big reactive cavity.

Abstract: This paper describes the preparation and characterization of nanocrystalline Magnesium Oxide (MgO) using sol-gel technique for optical applications. The prepared nanocrystalline MgO was chemically homogeneous, very pure and specifically hydroxylated and was characterized by standard techniques. The size of the prepared nanoparticle was found to be 27.38 nm ± 0.65 nm and exhibited a face centered–cubic structure and exhibited two lifetimes viz., 1 = 0.24 ns and 2 = 8.9 ns. Its binding energy was found to be 50.9 eV, which showed the formation of single phase MgO on the surface. It behaved as semiconductor over the temperature range of 500 °C to 660 °C and as perfect insulator in the temperature range 100 °K to 300 °K.