Abstract

We experimentally demonstrate, for the first-time to our knowledge, tunable true-time delay line operation over a few-mode fiber link, in which the time delay can be continuously and widely tuned, from 46.3 to 105.6 ps, by simply sweeping the operating optical wavelength over the 35-nm range of the C-band. This has become possible thanks to the particular modal dispersion properties of the developed double-clad step-index few-mode fiber, as it features relatively evenly-spaced incremental chromatic dispersion values among 5 spatial modes. To date, it is the first time a dispersion-diversity FMF with this property has been experimentally reported. We assess the performance of this true-time delay line when applied to microwave signal filtering in both space and wavelength diversities, where a variety of reconfigurable 5, 7 and 10-tap microwave filters with free spectral ranges ranging from 7.7 to 27.1 GHz are experimentally demonstrated.

Dispersion-tailored few-mode fiber design for tunable microwave photonic signal processing

Elham Nazemosadat and Ivana Gasulla
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Ring-core few-mode fiber for tunable true time delay line operation

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Opt. Express 27(22) 31773-31782 (2019)

Sampled true time delay line operation by inscription of long period gratings in few-mode fibers

Sergi García, Rubén Guillem, Javier Madrigal, David Barrera, Salvador Sales, and Ivana Gasulla
Opt. Express 27(16) 22787-22793 (2019)