Frequency-tuned continuous true-time delay by optical coherent transient technology

Summary form only given. A practical device creating a variable RF true-time delay (TTD) for signals on an optical carrier would be useful in array antennas. An optical coherent transient (OCT)-TTD device could provide high-resolution delays (/spl sim/1 ps) over a wide range (/spl sim/1 /spl mu/s), for high bandwidth signals (/spl sim/10 GHz) with currently available materials. In previously demonstrated OCT-TTD devices, two optical pulses separated in time and space program a delay in an absorbing medium as a spatial-spectral grating on an inhomogeneously broadened transition (IBT). In the paper, we experimentally demonstrate widely tunable OCT-TTD of a continuous optical data stream without changing the timing between the programming pulses.