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.