Assessment of high-purity quartz glass by laser induced fluorescence technique

In this paper, the laser-induced fluorescence (LIF) technology is utilized for rapid assessment of the purity of quartz glass, especially for the screening of high-purity quartz glass. A 355 nm laser was applied as excitation source to induce the fluorescence signal of the quartz glass samples. The fluorescence signal is then transmitted to the spectrometer through an optical fiber for spectral acquisition. Because only the impurities in quartz glass induce fluorescence, purity quartz glasses does not have a distinct fluorescence signals or fluorescence peaks. The purity evaluation of high-purity quartz glass can be achieved by analyzing the obtained signals. The standard deviation and the ratio of the maximum to minimum values of the signals were calculated to indicate the intensity of the fluorescent peak of the signal. The thresholds were then set to distinguish between high-purity and low-purity quartz glasses. The method has the advantages of high speed, high precision and high reliability, and is of great significance for the rapid screening of quartz glass with high purity requirements.