A collimated line beam is incident at an oblique incident angle of 0.61 rad into an inner surface of a hydrodynamic bearing whose inner diameter and length are 3 mm and 3.5 mm, respectively. Lights reflected in specified directions from the inner surface are selected to obtain an optical field whose phase distribution is proportional to the inner surface profile. This optical field interferes with a reference optical field in a two-wavelength interferometer using a tunable external cavity laser diode. Shapes of grooves with depth of about 5 μm and width of about 0.15 mm formed on the inner surface can be measured with an error less than 0.3 μm.

Date Published: 10 September 2009
PDF: 5 pages
Proc. SPIE 7432, Optical Inspection and Metrology for Non-Optics Industries, 74320J (10 September 2009); doi: 10.1117/12.827352

Published in SPIE Proceedings Vol. 7432:
Optical Inspection and Metrology for Non-Optics Industries
Peisen S. Huang; Toru Yoshizawa; Kevin G. Harding, Editor(s)