ABSOLUTE FREQUENCY MEASUREMENTS OF THE 28- AND 78-μm cw WATER VAPOR LASER LINES

Abstract
The two highest frequency measurements as yet reported are described. Frequencies of the 28‐ and 78‐μm cw water vapor laser lines were found to be 10.718073±0.000002 THz and 3.821775±0.000003 THz, respectively, by beating each of these radiations with the 337‐ and 373‐μm (0.89‐ and 0.80‐THz) radiation from an HCN laser, in a metal‐on‐metal point‐contact diode. The frequencies of the HCN laser were in turn measured by beating the 337‐μm radiation with 74‐GHz radiation and by measuring the 337‐ and 373‐μm frequency difference.
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