ABSTRACT
A typical pulse of a solid-state laser (ruby) consists of 1-ms long burst of spikes (see Figure 6.8). Robert W Hellwarth3 wrote a theoretical paper on spiking from which he drew later the idea of Q-switching. He observed that, if a method could be found preventing the laser to oscillate until the exciting ash is over, a population inversion greatly exceeding the usual threshold value could be established. If laser action is allowed at this moment, all available energy is concentrated into one giant pulse of extremely short duration.
