Surface modification of glass using xenon flashlamps

Abstract

An assessment study is reported using a xenon flashlamp of pulse length 1.8 msec and 25J cm⁻² energy for the beneficial modification of glass surfaces. Small diameter glass fibres (6 μm), preheated to 270°C, which fused and melted following flashlamp treatment, provided direct evidence that significant surface heating is possible. Scratches in bulk samples showed only limited evidence of surface healing when preheated to 500°C and flashlamp treated. However, bending and edge rounding of these samples provided indirect evidence for softening of a surface layer. A computer model was used to predict the effect of higher lamp power. The model data indicate that the system used would heat the surface significantly to a depth of 30 μm. However, the time duration, ∼ 3 msec, is too short for significant flow with bulk samples. Extended to longer pulse lengths (20 msec) and higher lamp incident energies (50J cm⁻²), the model predicts similar treatment depths but the duration of near maximum temperature rise (300°C) is increased from 3 msec to 15 msec.