Proceedings Article | 31 October 2016
Proc. SPIE. 10026, Real-time Photonic Measurements, Data Management, and Processing II
KEYWORDS: Optical fibers, Optical filters, Refractive index, Dispersion, Wave propagation, Signal processing, Electronic filtering, Microwave radiation, Filtering (signal processing), Phased array optics
Next generation fiber-wireless communication paradigms will require new technologies to address the current limitations
to massive capacity, connectivity and flexibility. Multicore optical fibers, which were conceived for high-capacity digital
communications, can bring numerous advantages to fiber-wireless radio access architectures. Besides radio over fiber
parallel distribution and multiple antenna connectivity, multicore fibers can implement, at the same time, a variety of
broadband processing functionalities for microwave and millimeter-wave signals. This approach leads to the novel
concept of “fiber-distributed signal processing”. In particular, we capitalize on the spatial parallelism inherent to
multicore fibers to implement a broadband tunable true time delay line, which is the basis of multiple processing
applications such as signal filtering, arbitrary waveform generation and squint-free radio beamsteering. We present the
design of trench-assisted heterogeneous multicore fibers composed of cores featuring individual spectral group delays
and chromatic dispersion profiles. Besides fulfilling the requirements for true time delay line operation, the MCFs are
optimized in terms of higher-order dispersion, crosstalk and bend sensitivity. Microwave photonics signal processing
will benefit from the performance stability, 2D operation versatility and compactness brought by the reported fiberintegrated
solution.
