Spiking laser emission

Fig.11.2. Spiking laser emission for laser media with long relaxation times...

The behavior of the laser output strongly depends on the time scale of relaxation processes. If they are slow, the induced emission drives the population inversion even below threshold and the laser output discontinues until the pump has reproduced sufficient population inversion to reach threshold, where induced emission starts again. The laser output consists in such cases of more or less irregular "spikes", with typical pulsewidths of a few ys, which appear during the whole time interval AT while the pump power is above threshold (Fig.11.2). The flashlamp-pumped ruby laser is a typical example of such a spiking laser. 

Nonpolymeric amorphous dyes for electron transport, some of them containing an oxadiazole ring, were prepared and theoretically studied. It was concluded that reversible electron injections and ejection properties without impurity effects could be obtained for the symmetric and globular amorphous molecules <1997PCA2350>. Amplified spontaneous emission laser spikes were observed for some simple 2,5-diaryl oxadiazoles <1997PCA3260>. 

Another technique for measuring the lifetime of excited activator atoms in solid-state lasers has been published by Gilrs h If the pulsed laser is operated close above threshold, only a single spike (i.e. a short pulse of induced emission) appears, whereas many spikes are emitted when the laser ist running well above threshold. This... 

Indeed, the laser oscillation itself frequently is a transient emission that falls into the broad definition of fluorescent lifetimes. In particular, spiking phenomena (5) and Q Switching (4) clearly bear a close relationship to relaxation times and processes. One could say that laser phenomena are associated with the study of fluorescent decays of inverted populations. 

Fig. 6.2 Schematic representation of spikes in the emission of a flashlamp-pumped solid-state laser with long relaxation times t/, ...

Fig. 9.21. Time-resolved recording of the light emission following laser-ablation from a sulphur target. The spike at 10)18 is the laser-induced fluorescence from the 7s state [9.122]...

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