Temporally overlapped linear frequency-chirped pulse programming for true-time-delay applications.

A novel technique for programming broadband true-time delays that uses two frequency-offset temporally overlapped linear frequency-chirped pulses to produce periodic spectral gratings in an inhomogeneously broadened absorber is presented. Advantages of this technique include its ability to use chirped pulses that are longer than the coherence time of the crystal, less stringent laser frequency-stability requirements for grating accumulation, lower power requirements, a simplified system design, and the ability to tune broadband (multigigahertz) delays over a wide dynamic range (picoseconds to microseconds).