Design of free-space couplers for suspended triangular nano-beam waveguides - data

These data are from a study involving the design and modelling of free-space couplers for suspended triangular nano-beam waveguides. We use Finite Element Analysis (FEA) using Ansys Lumerical Mode, and Finite-Difference Time-Domain (FDTD) modelling using Ansys Lumerical FDTD to benchmark and optimise the performance of three types of designs: Type A - Grating coupler with mode converter, Type B - Wedge mirror with Bragg reflector, Type C - Wedge mirror with mode converter.

The dataset includes 20 .CSV files with the raw data for each figure in the manuscript. The filename of the files points towards each labelled subplot in each figure.

Figure 2. Effective Index of triangular nano-beam waveguides

fig2_a.csv - Effective index of first 4 waveguide modes as function of waveguide width, for 1550 nm wavelength light.

fig2_b.csv - 2D array of normalised field intensity data for the first TE waveguide mode with top width of 765 nm. The X and Y axis are in stored in the first column and row respectively.

fig2_c.csv - 2D array of normalised field intensity data for the first TM waveguide mode with top width of 765 nm. The X and Y axis are in stored in the first column and row respectively.

Figure 3. Type A coupler design.

fig3_c_2DCouplingEfficiency.csv - 2D array of calculated coupling efficiency for Type A coupler of a Gaussian source focused from above into the TE-like waveguide mode as function of duty cycle and grating pitch for a grating coupler with w1 = 2000 nm and w2 = 400 nm. The X and Y axis are in stored in the first column and row respectively.

fig3_c_PhaseMatching.csv - Estimated pitch satisfying the 1st and 2nd order vertical grating (VG) and Bragg reflector (BR) phase matching conditions, as a function of duty cycle (DC).

fig3_d.csv - 2D array of normalised field intensity data for side view cross section field intensity distribution for Type A coupler with light input from the top with TE-like polarisation. The X and Y axis are in stored in the first column and row respectively.

fig3_e.csv - 2D array of normalised field intensity data for side view cross section field intensity distribution for Type A coupler with light input through the waveguide. The X and Y axis are in stored in the first column and row respectively.

fig3_f_r_theta_Intensity.csv - Normalised field intensity data for far field projection of Type A coupler with light input through the waveguide, as a function of r and theta.

fig3_g.csv - Simulated coupling efficiency as a function of wavelength for light input from the (labelled ”Top”) and through the waveguide (labelled ”WG”) in TE and TM-like polarisations.

Type A coupler final design specification:

Grating Periods: 5      

Grating Pitch: 1.2422 um

Grating Duty Cycle: 0.375

Grating Width1: 2 um

Grating Width2: 0.4 um

Mode Converter Length: 7.5 um

Mode Converter Width1: 0.765 um

Mode Converter Width2: 2 um

Figure 4. Type B coupler design.

fig4_c_2DCouplingEfficiency.csv - 2D array of calculated coupling efficiency for Type B coupler of a Gaussian source focused from above into the TE-like waveguide mode as function of duty cycle and grating pitch for a grating coupler with w1 = 4000 nm and w2 = 400 nm. The X and Y axis are in stored in the first column and row respectively.

fig4_c_PhaseMatching.csv - Estimated pitch satisfying the 1st and 2nd order vertical grating (VG) and Bragg reflector (BR) phase matching conditions, as a function of duty cycle (DC).

fig4_d.csv - 2D array of normalised field intensity data for side view cross section field intensity distribution for Type B coupler with light input from the top with TE-like polarisation. The X and Y axis are in stored in the first column and row respectively.

fig4_e.csv - 2D array of normalised field intensity data for side view cross section field intensity distribution for Type B coupler with light input through the waveguide. The X and Y axis are in stored in the first column and row respectively.

fig4_f_r_theta_Intensity.csv - Normalised field intensity data for far field projection of Type B coupler with light input through the waveguide, as a function of r and theta.

fig4_g.csv - Simulated coupling efficiency as a function of wavelength for light input from the (labelled ”Top”) and through the waveguide (labelled ”WG”) in TE and TM-like polarisations.

Type B coupler final design specification:

Grating Periods: 5      

Grating Pitch: 0.399054 um

Grating Duty Cycle: 0.661334

Grating Width1: 3 um

Grating Width2: 0.4 um

Mode Converter Length: 2.22046 um

Mode Converter Width1: 0.765 um

Mode Converter Width2: 3 um

Figure 5. Type C coupler design.

fig5_c_2DCouplingEfficiency.csv - 2D array of calculated coupling efficiency for Type C coupler of a Gaussian source focused from above into the TE-like waveguide mode as function of mode converter length, and wedge mirror width. The X and Y axis are in stored in the first column and row respectively.

fig5_d.csv - 2D array of normalised field intensity data for side view cross section field intensity distribution for Type C coupler with light input from the top with TE-like polarisation. The X and Y axis are in stored in the first column and row respectively.

fig5_e.csv - 2D array of normalised field intensity data for side view cross section field intensity distribution for Type C coupler with light input through the waveguide. The X and Y axis are in stored in the first column and row respectively.

fig5_f_r_theta_Intensity.csv - Normalised field intensity data for far field projection of Type C coupler with light input through the waveguide, as a function of r and theta.

fig5_g.csv - Simulated coupling efficiency as a function of wavelength for light input from the (labelled ”Top”) and through the waveguide (labelled ”WG”) in TE and TM-like polarisations.

Type C coupler final design specification:

Mode Converter Length: 3.7626 um

Mode Converter Width1: 1.77528 um

Mode Converter Width2: 3 um

Wedge Mirror Length: 2.85 um

Wedge Mirror Width1: 3.07064 um

Wedge Mirror Width2: 0.4 um

Reserach results based upon these data are published at http://doi.org/10.1088/1361-6463/ac941e