Frequency of lamb-dip-stabilized 1.52 μm He-Ne lasers

A 3He-20Ne and a 3He-22Ne 1.52 μm laser were frequency stabilized to the Lamb-dip of their respective gain curve and provided a resettability of 2 MHz. Using these lasers, absolute frequencies for the 20Ne and 22Ne laser transitions were measured by interferometric frequency comparison with an I2-stabilized He-Ne laser at 0.633 μm. A least-square analysis which accounts for the linear frequency dependence of the laser gas pressure yielded two parameters which can reproduce the measured frequencies within an accuracy of ±1.0·10−8 at 1.52 μm.