CO2laser mode-locking

This paper reports the analysis and observation of CO2laser mode-locking produced by interactivity loss modulation. Previous more-locked lasers have involved the coupling of a number of already-oscillating modes. It was recently predicted by McDuff and Harris (IEEE J. Quant. Electr., QE-3, 101, 1967) that even in lasers such as CO2which have such narrow fluorescence linewidths that only oxial mode is above the threshold for oscillation, it is possible to transfer sufficient energy from that mode to neighboring below threshold axial modes to effect mode-locked, pulsed operation. For the small-signal-saturation case which they considered, both narrow output pulse widths and large peak power enhancement were predicted. This is the same behavior as is characteristic of normal mode-locked multi-mode lasers. Modifying their analysis to include the effects of nonlinear saturation, we find that the narrow pulses are obtained, but with only slight increase in peak power.