We evaluate the subsurface quality of polished fused silica samples using the nanoindenter technique. Two kinds of samples, consisting of hundreds of nanometers and micrometers of subsurface damage layers, are fabricated by controlling the grinding and polishing processes, and the subsurface quality has been verified by the chemical etching method. Then several nanoindentation experiments are performed using the Berkovich tip to investigate the subsurface quality. Some differences are found by relative measurements in terms of the relationship between the total penetration and the peak load on the surfaces, the modulus calculated over the defined depths and from unload, and the indented morphology at a constant load near the surface collapse threshold. Finally, the capabilities of such a mechanical method for detecting subsurface flaws are discussed and analyzed.
© 2011 Optical Society of America
Original Manuscript: August 2, 2010
Revised Manuscript: November 20, 2010
Manuscript Accepted: December 6, 2010
Published: January 18, 2011
Bin Ma, Zhengxiang Shen, Pengfei He, Fei Sha, Chunliang Wang, Bin Wang, Yiqin Ji, Huasong Liu, Weihao Li, and Zhanshan Wang, "Evaluation and analysis of polished fused silica subsurface quality by the nanoindenter technique," Appl. Opt. 50, C279-C285 (2011)