Tunable True-Time Delay Operation in A Dispersion-Engineered Few-Mode Fiber

We present a simple few-mode fiber design as a promising platform to implement tunable sampled true-time delay lines for radiofrequency signal processing. To the best of our knowledge, this is the first few-mode fiber ever reported featuring evenly spaced incremental dispersion values, which is an essential characteristic required for tunable operation of microwave photonics applications. The performance of the designed five-sample true-time delay line is theoretically validated in the context of microwave signal filtering, demonstrating free spectral range continuous tunability from 12.4 up to 57 GHz.