Microwave processing has achieved widespread interest in recent years as a rapid and efficient means of processing glass and ceramic materials. Unfortunately, not all materials are equally well-suited for microwave sintering due to wide variations in microwave susceptibilities for different materials. Silica and high silicates, for example, are relatively poor microwave susceptors. Employing a recently disclosed process, called secondary microwave heating, porous silica and doped silica gels have been successfully sintered into dense glasses. This method of microwave sintering relies upon a highly efficient microwave susceptor, known as a microwave suscepting ceramic composite (MSCC), to transfer energy to the sample being processed. Typical sintering times to achieve fully dense glasses from sol-gel are approximately 10 minutes. In this paper, the optical properties of conventionally sintered and microwave sintered silica and doped silica glasses will be compared. Dopants include chromium, copper, neodymium, erbium, and europium. Key properties to be examined include light scattering, UV-vis-nIR spectrophotometry, and fluorescence. In addition, the potential application of this process to small, sol-gel derived specialty shapes, such as lens, etc, will be discussed.
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