We show that a temporal effect that is equivalent to the spatial self-imaging (Talbot) effect applies to the reflection of periodic signals from linearly chirped fiber gratings. The effect can be used for multiplying the repetition frequency of a given periodic pulse train without distorting the individual pulse characteristics. The practical limit on the frequency-multiplication factor depends only on the temporal width of the individual pulse. Thus we demonstrate that a suitable combination of well-known techniques for short-pulse generation, such as pulse mode locking, and the technique proposed here allows us to obtain short-pulse trains with ultrahigh repetition rates (in the terahertz regime). Results from simulations show good agreement with those predicted by theory.
© 1999 Optical Society of America
(060.2340) Fiber optics and optical communications : Fiber optics components
(060.5530) Fiber optics and optical communications : Pulse propagation and temporal solitons
(060.7140) Fiber optics and optical communications : Ultrafast processes in fibers
(070.6760) Fourier optics and signal processing : Talbot and self-imaging effects
(260.2030) Physical optics : Dispersion
José Azaña and Miguel A. Muriel, "Technique for multiplying the repetition rates of periodic trains of pulses by means of a temporal self-imaging effect in chirped fiber gratings," Opt. Lett. 24, 1672-1674 (1999)