Temporal and Energy Characteristics of the First-Positive-Band-System Molecular Nitrogen Laser

Abstract

As in the case of hydrogen, lasing in the 1+ band system of N₂ is observed at the leading edge of the current pulse. Sample oscillograms of the stimulated emission and current pulses for low and high voltages, of the type shown in Fig. 9, bear out this conclusion. The low-voltage emission pulse has the usual characteristic shape, i.e., a relatively gradual leading edge and sharp cutoff. It is clear that when the voltage is increased the laser emission pulse width Δt_L is sharply curtailed, by about an order of magnitude under the conditions of Fig. 9. Also decreased is the time interval t_max in which the maximum laser power is attained. The voltage dependence of Δt_L and t_max is shown in Fig. 10. Both of these variables decrease rapidly as the voltage is increased. Under these conditions the laser emission pulse energy varies somewhat differently with increasing voltage than the peak power (Fig. 11); after reaching a maximum, the energy curve drops off more rapidly than the laser power.