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Unit of Length

Working Group 4.31

Ultra-stable Lasers for Length Measurement: Laser Wavelength Standards

For precision length measurements in the range from nanometers to a few metres, interferometric methods are used in the case of which the length to be measured is compared with one or several known light wavelengths. For this purpose, PTB is developing laser light sources in the case of which the required wavelength stability is achieved by suitable stabilization measures, e. g. by comparison with small atomic absorption lines. The laser wavelength standards developed at PTB comprise standards whose wavelength variations amount to less than one part in a billion of the wavelength.


Dr. Uwe Sterr
Phone: +49 (0)531-592 4310
Fax: +49 (0)531- 592 4305
E-mail: Uwe Sterr