Measurement of the frequency of a submillimeter NH3 laser (λ=81.5μ)

Measurements of the frequency of a submiliimeter NH₃ laser (λ = 81.5 μ) optically pumped by N₂O laser radiation are reported. The measurements were made by comparison with the difference frequency of two CO₂ lasers. Frequency mixing was achieved using a point-contact metal-oxide-metal diode. The measured frequency was ν_NH3 = 3 678 577 ±6 MHz. It is suggested that this laser may be used in systems for frequency measurement and synthesis in the optical range.