Ye, Feihong1; Tu, Jiajing4; Saitoh, Kunimasa4; Morioka, Toshio1
1 Department of Photonics Engineering, Technical University of Denmark2 High-Speed Optical Communication, Department of Photonics Engineering, Technical University of Denmark3 Hokkaido University4 Hokkaido University
An analytical expression for the mode coupling coe cient in homogeneous trench-assisted multi-core fibers is derived, which has a sim- ple relationship with the one in normal step-index structures. The amount of inter-core crosstalk reduction (in dB) with trench-assisted structures compared to the one with normal step-index structures can then be written by a simple expression. Comparison with numerical simulations confirms that the obtained analytical expression has very good accuracy for crosstalk estimation. The crosstalk properties in trench-assisted multi-core fibers, such as crosstalk dependence on core pitch and wavelength-dependent crosstalk, can be obtained by this simple analytical expression.