Research progress in optical tunable delay line and its applications
Some research works of all-optical tunable delay lines are introduced based on wavelength conversion in semiconductor optical amplifiers (SOAs) and group-velocity dispersion (GVD) in optical fibers. By employing dispersion-compensating fiber (DCF) and single-mode fiber (SMF) as dispersion materials, large tunable time delay are obtained for long and short wavelength input in C band respectively. The combination of these two schemes realize large time delay under wide band input in the whole C band. The applications of optical delay line (ODL) in optical ultrawideband (UWB) signals generation and optical Manchester signal processing are exhibited subsequently. Wide applications and great potential of optical delay lines are shown.