We developed a method which allows comparisons of the wavelengths emitted by two lasers with an accuracy of about 6·10
–6.
The method and the setup are very advantageous for the infrared wavelength range, because the methods which are characterized by high measurement accuracy in the infrared region cannot be employed, and conventional methods cannot provide an accuracy better than 1·10
–5 (for the range 3–10
). One can use photodiodes or photoresistors as the converting elements which can be operated without cooling and are characterized by a sufficiently high sensitivity.
Translated from Izmeritel''naya Tekhnika, No. 6, pp. 42–43, June, 1971.