This letter describes correlated and uncorrelated timing jitter of gai
n-switched pulses generated from sinusoidally modulated laser diodes m
easured from photocurrent power spectra. It is found that if dc bias i
s 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 level of the dr
ive circuit of approximately 0.2 ps. By optimizing the bias condition
and compression fiber length, total timing jitter of gain-switched pul
ses can be reduced to as low as approximately 0.5 ps, as their pulse w
idth is kept less than 10 ps.