We report the precise transfer of radio-frequency signals by use of the pulse repetition frequency of mode-locked laser sources at 1.5 μm transmitting through a fiber network. The passive transfer instability through a 6.9-km fiber is below 3×10<sup>-14</sup> at 1 s, which is comparable with the optical carrier-frequency transfer of a narrow-linewidth cw laser. The instability of the measurement system is below 7×10<sup>-15</sup> at 1 s. It is noted that the pulsed mode of operation offers almost an order-of-magnitude improvement in stability at 1 s over that with a sinusoidal amplitude modulation on an optical carrier.
© 2004 Optical Society of America
(120.3930) Instrumentation, measurement, and metrology : Metrological instrumentation
(140.4050) Lasers and laser optics : Mode-locked lasers
(320.7160) Ultrafast optics : Ultrafast technology
Kevin W. Holman, David J. Jones, *Darren D. Hudson, and Jun Ye, "Precise frequency transfer through a fiber network by use of 1.5-μm mode-locked sources," Opt. Lett. 29, 1554-1556 (2004)