Coarse and Fine Continuously Tunable Optical Delay Using the Time-of-flight in Fiber Bragg Gratings and Wavelength Conversion

We use the time-of-flight in arrayed, channelized and chirped fiber Bragg gratings along with wavelength conversion in PPLN waveguides to build continuously coarse- and fine-tunable delay line. More than 20 ns continues tuning range is achieved with less-than-0.6dB OSNR penalty for a 10 Gbaud QPSK signal.