Turn-on Delay Time Fluctuations in Unbiased Gain-Switched AlGaAs/GaAs Multiple Quantum Well Lasers

The turn-on delay time jitter in unbiased gain-switched AlGaAs-GaAs multiple quantum well lasers is investigated in detail. The rms timing jitter is determined by measuring the transient fluctuations of the total emitted power using a fixed-time sampling technique with a picosecond temporal resolution. The turn-on jitter is found to decrease significantly with increasing pumping rate, particularly when the lasers are operated at an excitation level where only the first relaxation oscillation is emitted. The rms jitter of the emitted optical pulses decreases from about 20 ps just above the laser threshold to a value of 14 ps at the threshold for the appearance of the second relaxation oscillation. These results demonstrate that the accurate adjustment of the pumping rate is essential for a low jitter single pulse operation of the gain-switched lasers.