Calibration and Testing of Laser Wavelength Standards
For dissemination of the unit of length, working lasers and secondary standards are linked up and calibrated with the laser wavelength standards of PTB via beat frequency measurements and wavelength comparisons. For this purpose, iodine-stabilized He-Ne lasers at 633 nm or frequency-doubled Nd:YAG lasers at 532 nm are used which comply with the recommendations of the International Committee for Weights and Measures (CIPM). When stabilization is performed by means of saturated absorption to the components d - j of the transition 11 - 5 R(127) of the
127I 2-molecule, the measurement uncertainties are - compared to a PTB reference laser - less than 12 kHz.
At regular intervals, the frequencies of the reference lasers are traced back by means of frequency measurements.
Contact
Dr. Uwe Sterr Phone.: +49 531-592 4310 E-mail: Uwe Sterr | Klemens Budin |