FIBRE OPTICAL COUPLER SIMULATION BY COMSOL MULTIPHYSICS SOFTWARE

Funding: The research has been supported by the European Regional Development Fund project No.1.1.1.1/18/A/068. The Institute of Solid State Physics, University of Latvia as a Center of Excellence has received funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART2.The paper presents a simulation model developed for a special optical coupler intended for coupling radiation from signal and pump sources used for the realization of cladding-pumped doped fibre amplifiers. The model is developed in COMSOL Multiphysics and used to assess the pumping efficiency for different side pumping angles and different numbers of electromagnetic modes. The obtained results show that the highest pumping efficiency, above 75 %, is achieved for 5–14 modes when two fibres representing the pump source and the signal source form a 10-degree angle between their central axes. The search for the optimal number of modes corresponds to the development trend in optical coupler technology where the multimode pumping by light-emitting diode (LED) replaces the classical scheme with a single-mode pumping by a laser diode (LD). © 2022 Sciendo. All rights reserved. --//-- This is an open access article Elsts E., Supe A., Spolitis S., Zakis K., Olonkins S., Udalcovs A., Murnieks R., Senkans U., Prigunovs D., Gegere L., Draguns K., Lukosevics I., Ozolins O., Grube J., Bobrovs V. FIBRE OPTICAL COUPLER SIMULATION BY COMSOL MULTIPHYSICS SOFTWARE (2022) Latvian Journal of Physics and Technical Sciences, 59 (5), pp. 3 - 14, DOI: 10.2478/lpts-2022-0036 published under the CC BY-NC-ND 4.0 licence.ERDF No.1.1.1.1/18/A/068; The Institute of Solid State Physics, University of Latvia as a Center of Excellence has received funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART2

Investigation of EDFA Performance in DWDM Transmission Systems Under Different Operating Conditions

The article investigates dependence of EDFA performance on its operating conditions. First of all, the impact of changes in channel spacing on the quality of the amplifier signal and on the desired EDFA configuration is observed – three different values of channel spacing are considered – 37.5 GHz, 50 GHz and 100 GHz. Afterwards, the impact of EDFA positioning on the quality of the amplified signal and the desired configuration is assessed. Three different EDFA positioning scenarios are considered – when the EDFA is used as a power booster, as an in-line amplifier and as a preamplifier. In all cases, such configuration of the EDFA is found that can ensure bit-error ratio (BER) values below 1·10−9 in all channels of the system. To assess the performance of the amplifiers, power penalty values are obtained in respect to identical transmission systems but without amplification