Interferometric length measurements

Erkki Ikonen; Antti Lassila; J. Luukkainen; Kari Riski

doi:10.1117/12.140790

15 February 1993 Interferometric length measurements

Erkki Ikonen, Antti Lassila, J. Luukkainen, Kari Riski

Proceedings Volume 1756, Interferometry: Applications; (1993) https://doi.org/10.1117/12.140790
Event: San Diego '92, 1992, San Diego, CA, United States

Abstract

Automated interferometer equipments are described which can be used for calibrations of gauge blocks and line scales with lengths up to 1000 mm. For the gauge blocks, the scanning measurement method utilizes a white-light source and one stabilized 633-nm laser. White-light interference signals from the reference flat and from the front surface of the gauge block mark the distance to be measured with the laser. The final length is determined from the laser-signal phase shifts between the gauge and the reference flat. Environmental conditions are measured and the necessary corrections are made automatically. The repeatability of the measurements is +/- 3 nm for a 400-mm gauge block and the estimated relative uncertainty (1 s) is about 10^-7. The variation in length of the gauge block is obtained by computer-aided analysis of the digitized interference fringe patterns. For the line scales, a new measurement method has been developed which can utilize the same electronic units as used for gauge-block calibration: images of the graduation lines replace the white-light interferences. The two fields constituting a video frame (image) are recorded by a moving microscope and by a ccd camera with 1-ms charging time interval. The exact distance between the microscope positions at the time of charging the ccd pixels is deduced from the interference and video synchronization signals. It is expected that a total uncertainty of about 100 nm for a 1000-mm scale will be reached.

Citation Download Citation

Erkki Ikonen, Antti Lassila, J. Luukkainen, and Kari Riski "Interferometric length measurements", Proc. SPIE 1756, Interferometry: Applications, (15 February 1993); https://doi.org/10.1117/12.140790

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available