Share Email Print
cover

Proceedings Paper

Interferometric determination of the silicon sphere diameter using a laser frequency tuning system calibrated by a Fabry-Perot cavity
Author(s): Xuejian Wu; Jitao Zhang; Haoyun Wei; Yan Li
Format Member Price Non-Member Price
PDF $14.40 $18.00

Paper Abstract

In order to obtain an accurate Avogadro constant with a relative uncertainty of 1×10-8 to redefine the kilogram, the diameter of a perfect single crystal silicon sphere is required with the measurement uncertainty of 0.3 nm using the X-ray crystal density method. To achieve this, phase-shifting interferometers have been developed. A laser frequency tuning system calibrated by a Fabry-Perot cavity is proposed to improve the laser wavelength and the phase-shift accuracy. The laser frequency standard deviation of the beat frequency is 85 kHz with a gate time of 0.1 s. The gap distances in the diameter determination interferometer are measured based on the laser tuning system, which are 275.3 nm and 110.5 nm, respectively.

Paper Details

Date Published: 20 November 2012
PDF: 6 pages
Proc. SPIE 8563, Optical Metrology and Inspection for Industrial Applications II, 85631G (20 November 2012); doi: 10.1117/12.982012
Show Author Affiliations
Xuejian Wu, Tsinghua Univ. (China)
Jitao Zhang, Tsinghua Univ. (China)
Haoyun Wei, Tsinghua Univ. (China)
Yan Li, Tsinghua Univ. (China)


Published in SPIE Proceedings Vol. 8563:
Optical Metrology and Inspection for Industrial Applications II
Kevin G. Harding; Peisen S. Huang; Toru Yoshizawa, Editor(s)

© SPIE. Terms of Use
Back to Top