3.△K的计算从公式看出,引起K值变化的原因是被测谱线波长和激光波长的测量误差以及它们的漂移,对上式求全微分目前氦氖激光波长的测定精度可达±0.0025微微米,此项误差可予忽略。在采用石英玻璃做套管和未加稳频器的情况下,单模氦氖激光器通常能达到的稳频精度为 3. Calculation of △ K From the formula we can see that the reason for the change of K value is the measurement error of the wavelength of the measured line and the laser wavelength and their drift, so as to obtain the full differential of the above formula. The measurement accuracy of the He-Ne laser wavelength can reach ± 0.0025 picometer, this error can be ignored. In the case of using quartz glass as a sleeve and without a frequency stabilizer, the single-mode He-Ne laser usually achieves the frequency stabilization accuracy of