Residual stress measurement based on Raman spectroscopy of backscattered light from microcracks in machined glass surface layer

-Raman spectroscopic study for stress measurement in the vicinity of an indentation crack-

Abstract

Microcracks are induced on a glass lens surface during machining process. It is necessary to develop a measurement method for the stress state of microcracks based on the backscattered light from microcracks. We propose an evaluation method of changes in the molecular structure caused by stresses around the cracks based on Raman spectroscopy of the backscattered light. In this report, Raman measurements were carried out at an indentation and an indentation crack. Raman spectrums changes at the sample surface of the indentation. The possibility for detection of changes in the molecular structure of glass around a microcrack from Raman measurement is confirmed.