Correlated and uncorrelated timing jitter in gain-switched laser diodes

The author describes correlated and uncorrelated timing jitter of gain-switched pulses generated from sinusoidally modulated laser diodes measured from photocurrent power spectra. It is found that if dc bias is decreased to obtain shorter pulses, then the root-mean-square (rms) value of uncorrelated timing jitter drastically increases to more than 2 ps, while correlated jitter remains constant at the drive circuit level of approximately 0.2 ps. By optimizing the bias condition and compression fiber length, total timing jitter of gain-switched pulses can be reduced to as low as approximately 0.5 ps, as their pulse width is kept less than 10 ps.<>