CO isotope lasers

Line-Center Stabilized, Grating Controlled CO Isotope Lasers... 

In principle at least, CO isotope lasers can most conveniently serve as reference lasers in the 4.9 to 8.0 pm wavelength domain. In terms of spectral purity, sealed-off operation ) a d abundance of readily available lasing transitions CO isotope lasers are at least as good as their COi counterparts. Lamb-dip stabilization of CO lasers was also accomplished 3) nearly 15 years ago. However, the resettability of the Lamb-dip stabilization method is at least 100 times less accurate than the 4.3 pm fluorescence stabilization of CO2 lasers. The absolute accuracy of presently available CO laser transition frequencies is also only good to within about one or two MHz. If one MHz or so accuracy is not sufficient, a direct comparison of a CO reference laser line with an appropriately selected frequency doubled line-center stabilized CO2 laser transition is always possible and was so demonstrated several years ago. ... 

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