Figure 2

Waveforms of the gain-switched pulses from the InGaN VCSEL at (a) room temperature and (b) 3.4 K measured via up-conversion method.
The inset shows the lasing spectrum at 3.4 K. The cross-correlation waveforms of the pump pulses, which was observed without the band-pass filter shown in Fig. 1b, are also plotted. The optical time delay arising in the filter is compensated for in these waveforms.