When v2+v4 of CF4 at 1066 cm-1 is pumped by the 9.4-µm CO2 laser, stimulated emission on the (v2+v4) + v2 transition produces many discrete laser lines in the region 605 to 655 cm-1. A comprehensive program of Doppler-limited absorption spectroscopy of CF4 has been carried out using tunable semiconductor diode lasers, and has led to a full understanding of the rovibrational energy levels involved in the laser process. The frequencies of 28 laser lines of 12CF4 have been measured with an accuracy of ±0.2 cm- 1, for 12C16O2 pump lines from P(14) to R(24). From the complete vibration-rotation analysis of the v2+v4 band, the pump and laser transitions have been identified. Using the spectroscopic constants determined in the band analyses, we can predict within ±0.2 cm-1 the laser lines to be expected from any given pumping frequency. All observed laser lines have been accounted for; in a few cases there is evidence for a relaxation of J-value and/or Coriolis sublevel in the upper state. Application of these results to improving the performance of the CF4 laser and for designing it to produce specific desired output frequencies is discussed.