A dc-voltage-controlled optoelectronic delay line for continuous tuning of the relative delay time of an optical pulse train generated from a gain-switched laser diode is demonstrated. A maximum tunable range delay time of 3.9 ns (≈2 periods) for optical pulses at a 500-MHz repetition rate is reported, which corresponds to a phase shift of as much as 4π. The tuning responsivity and resolution of the current apparatus are 0.54 ps/mV and <0.2 ps, respectively. The measured timing fluctuation and long-term drift at any delay time are 0.13 ps and 20 fs/min, respectively. This scheme further permits the simultaneous phase tracking of the laser pulse train to unknown signals generated from the device under test.
© 2000 Optical Society of America
(120.0120) Instrumentation, measurement, and metrology : Instrumentation, measurement, and metrology
(120.5050) Instrumentation, measurement, and metrology : Phase measurement
(320.7160) Ultrafast optics : Ultrafast technology
Gong-Ru Lin, "Optoelectronic delay-time controller for laser pulses," Opt. Lett. 25, 799-801 (2000)