True time-delay line with high resolution and wide range employing dispersion and optical spectrum processing

True time-delay line with a high resolution and wide range is proposed and demonstrated. Tunable lasers and dispersion fibers are employed to control the time delay coarsely. An optical spectrum processor is utilized to realize high-resolution time-delay control by adding a quadratic optical phase shift, which compensates the group velocity dispersion of the fiber simultaneously. A coarse tuning range of 1717 ps is realized by changing the wavelength of the optical carrier, and a high resolution of 0.67 ps is achieved by translating the symmetry axis of the quadratic phase shift.