This file can be used to reproduce Fig. 1 (a-c) of the article where BPM-Matlab is used to simulate beam propagation through a multimode fiber. The x and y axes values are available in the variables P.x and P.y. The E-field intensity at the proximal end in Fig. 1(a) can be calculated as abs(P.Einitial.').^2. The corresponding phase in Fig. 1(b) is available as angle(P.Einitial.'). The E-field intensity at the multimode fiber distal end in Fig. 1(c) can be calculated as abs(P.E.field.').^2.
The corresponding BeamLab simulation results of the same multimode fiber are available in this data file. This data file is generated using BeamLab software. Use the variables bpmData.SlicesXZ.XData, bpmData.SlicesYZ.YData, and abs(bpmData.OutputField.E.x.').^2 to obtain x, y, and distal E-field intensity respectively.
The data from this file will generate intensity profiles of the five lowest order fiber modes supported by a straight and a bent multimode fiber corresponding to Figure 2 of the article. The variables P_noBend and P_bend are struct variables that hold information about the spatial dimensions as well as E-field profiles of the straight and bent modes. For the straight fiber case, the mode field profile is stored in P_noBend.modes(modeNumber).field, where 1
x = dx*(-(Nx-1)/2:(Nx-1)/2) and
y = dy*(-(Ny-1)/2:(Ny-1)/2), where
Nx = size(P_noBend.modes(modeNumber).field,1),
Ny = size(P_noBend.modes(modeNumber).field,2),
dx = P_noBend.modes(modeNumber).Lx/Nx, and
dy = P_noBend.modes(modeNumber).Ly/Ny.
In a similar manner, the mode field profiles of bent multimode fiber may also be accessed from P_bend.
Use this data file to reproduce Figure 3(a) from the article, where numerical simulation results of different LP modes' normalized fractional power in a bent multimode fiber excited with LP01 mode are presented. The matlab command
will plot the mode overlap of LP01 to all 30 guided modes in logarithmic scale. The following command
could be used to label the modes. Set the y-limits of the plot using ylim([1e-4 2]) to visualize the contribution from only the six most excited modes.
Load this data file and follow similar steps described above for Data_Fig3_a case in order to plot normalized fractional power in a bent multimode fiber excited with LP03 mode, as in Figure 3(b).
To reproduce Figure 4(a) from the article, use the commands
to plot the intensity profile in the xz plane of a multimode fiber tapered down to be a single-mode fiber.
For Figure 4(b), use plot(P.z,P.powers) that will plot the power within the simulation window against the length P.z of the fiber.
This data file could be used to plot the intensity profile of the E-field at a distance of z = 5 mm after the non-twisted, straight multicore fiber distal end as given in Figure 5(a) in the article. The E-field data after propagation from the distal end is available as E_out_fft.field and the corresponding spatial dimensions are available as E_out_fft.x and E_out_fft.y. Use
imagesc(x.*1e3,y.*1e3,E_abs(E_out_fft.field.').^2); axis image;
to plot the field intensity profile.
Similar to the above case, use the below .mat files to reproduce Figure 5 (b-d).
Data_Fig5_b.mat - Twisted straight multicore fiber
Data_Fig5_c.mat - Non-twisted bent multicore fiber
Data_Fig5_d.mat - Twisted bent multicore fiber.