Information processing with longitudinal spectral decomposition of ultrafast pulses.

We describe what we believe to be novel methods for waveform synthesis and detection relying on longitudinal spectral decomposition of subpicosecond optical pulses. Optical processing is performed in both all-fiber and mixed fiber-free-space systems. Demonstrated applications include ultrafast optical waveform synthesis, microwave spectrum analysis, and high-speed electrical arbitrary waveform generation. The techniques have the potential for time-bandwidth products of > or =10(4) due to exclusive reliance on time-domain processing. We introduce the principles of operation and subsequently support these with results from our experimental systems. Both theory and experiments suggest third-order dispersion as the principle limitation to large time-bandwidth products. Chirped-fiber Bragg gratings offer a route to increasing the number of resolvable spots for use in high-speed signal processing applications.