New and flexible fiber-optic delay-line filters using chirped Bragg gratings and laser arrays

Integrable microwave filter based on a photonic crystal delay line

“…Thus, the value of the basic delay T is changed by tuning the wavelength separation among the carriers, thereby allowing tunability 25 . Although in the first case the intensity or weight a k of the k-th tap can be changed by inserting loss/gain devices in the fibre coils, with the second approach, a k is readily adjusted by changing the optical power emitted by the optical sources 12,25 . In this work, we focus on the approach of Fig.…”

“…MWP signal processors reported so far [12][13][14][15][16] have relied on discrete optoelectronic devices and standard optical fibre delay lines, and components leading to bulky, expensive and powerconsuming architectures. Typical delay line footprints range from several tens of centimetres when using fibre Bragg gratings (FBGs) to a few kilometres when using standard optical fibres.…”

Fractional Fourier transform-exceeding the classical concepts of signal’s manipulation

“…Photonic RF filters have a lot of potential due to their capability to obtain high dynamic range, tunability and reconfiguration. Several configurations have been suggested employing highly dispersive fibers [33], fiber gratings [34], fiber optics prisms [35] or arrayed waveguide gratings (AWG) [36] or optical spectrum analyzers [37]. In this paper we present the usage of the FRT to separate between multiple chirped RF photonic signal.…”

Microwave Signal Processing over Multicore Fiber

“…Configurations built upon single-core SMFs featured operation bandwidths ranging from 0.1 up to 40 GHz and RF delays ranging from 0.4 up to 8 ns. These configurations include the use of switched fiber architectures and dispersive fibers [40], the inscription of different Fiber Bragg Grating (FBG) devices [41][42][43] as well as the exploitation of nonlinearities such as Stimulated Brillouin Scattering [44]. On the other hand, integrated photonics technologies have demonstrated operation bandwidths from 2 to 50 GHz and RF delays from 40 to 140 ps.…”

“…This leads to what we call "fiber-distributed signal processing", a concept with great potential regarding converged fiber-wireless telecommunications scenarios, as those envisioned for 5G systems and the Internet of Things. A true time delay line (TTDL) can be considered the key building block of radiofrequency signal processing [36][37][38][39][40][41][42][43][44][45][46][47]. This photonic subsystem provides a frequency independent and tunable group delay for the RF signal within a given frequency range.…”