IR laser wavelength measurement

Conclusions

The values of the 1.15μ wavelengths under vacuum obtained by two independent methods are

$$\lambda _x = 1.15259016 \pm 6 \cdot 10^{ - 8} \mu$$

and differ in magnitude by not more than the error of measurement. This is a sufficiently reliable criterion for the systematic errors to be small. The standard laser wavelength of 0.63μ has been checked by repeated measurements against⁸⁶Kr [9] and has been confirmed by a certificate issued by the All-Union Metrology-Research Institute [4].

This wavelength relates to the above particular laser, but the effects of the pressure on the line shift show thatλ _X with other parameters for the discharge tube may differ from the value given there by a few units in the 7th place. This is no obstacle to the use of a 1.15-μ laser as a standard for length measurement in spectroscopy in the near IR.

The above methods and schemes enable one to bring the accuracy of measurement for infrared laser wavelengths close to that of standard wavelengths, namely about 1.10⁸ for⁸⁶Kr, out to 3.5μ.