A 5 Gb/s 32-QAM data transmission over a hybrid standard single-mode fibre (SSMF) and free-space optics (FSO) link has been experimentally demonstrated in the 42 − 90 GHz range for 5G networks deployment. Four-wave mixing (FWM) nonlinear effect in a semiconductor optical amplifier (SOA) experienced by a carrier suppressed double sideband modulated signal has been employed to photonically generate millimetre wave (mmW) signals with reduced electronics bandwidth. Both simulation and experimental results have been shown to describe the error vector magnitude (EVM) performance of the system. Large operation bandwidth is shown in our experimental setup, where measured penalties for 42 and 66 GHz are below 1 dB whereas 90 GHz leads to 3 dB penalty at 12 % EVM threshold. Sensitivity has also been estimated for optical back-to-back (OB2B), after SSMF and hybrid link transmissions for different mmW frequencies.
In our contribution we report novel mode field adapter incorporated inside bundled tapered pump and signal combiner. Pump and signal combiners are crucial component of contemporary double clad high power fiber lasers. Proposed combiner allows simultaneous matching to single mode core on input and output. We used advanced optimization techniques to match the combiner to a single mode core simultaneously on input and output and to minimalize losses of the combiner signal branch. We designed two arrangements of combiners’ mode field adapters. Our numerical simulations estimates losses in signal branches of optimized combiners of 0.23 dB for the first design and 0.16 dB for the second design for SMF-28 input fiber and SMF-28 matched output double clad fiber for the wavelength of 2000 nm. The splice losses of the actual combiner are expected to be even lower thanks to dopant diffusion during the splicing process.
Results from tests and analyses of multimode optical fibers for an avionic optical network under a variety of stress conditions are presented. Experiments revealed vibrational and temperature changes of distinct multimode fibers. Results lead to the discussion of influenced insertion losses and especially reduced bandwidth corresponding to modal distribution changes. It was determined that these crucial parameters could affect system reliability when an airplane network intersects thermal and vibrational variable environments.