# Propagation losses in photonic crystal waveguides embedding InAs/GaAs quantum dots determined by direct spectral imaging

The white light reflection image of the waveguide is a bitmap file.

The spectral image is given in ASCII matrix, with dimensions 1340x60 pixels. The energy axis can be calibrated using P1*x + P2, P1=-7.34555954E-3 nm/pixel, P2=8.86977966E+2 nm, initial pixel x=0. The x position axis can be calibrated using P1*y + P2, P1=5.95401108E-1 um/pixel, P2=-3.26574554E+1 um, initial pixel x=24. Intensity scale: from -3.26574554E+1 to 3.0072E+4 counts; multiply by 2/60 to obtain intensity in photoelectrons per time per pixel. The QD spectrum is obtained as a cut along x. The cut is averaging from pixels y=31 and y=35.

The spectrally integrated emission ratio is given in a .dat file of 16 columns, which contains: 4 columns per spectrometer center position. These are excitation position in micrometers and spectrally integrated emission ratio for experimental data (first two columns) and fit (last two columns). The spectrometer center position are 1.378eV (1-4 columns), 1.393eV (5-8 columns), 1.409eV (9-12 columns), 1.425eV (13-16 columns). Losses from photoluminescence (PL), relative efficiency of the grating out-couplers from PL and losses from near-field (NF) imaging are all given in a .dat file with 8 columns: energy scale of losses from PL (eV), losses from PL (um^(-1)), standard deviation (std) error of losses from PL (um^(-1)), relative efficiency of the grating out-coupler (unitless), std error of relative efficiency of the grating out-coupler (unitless), energy scale of losses from NF (eV), losses from NF (um^(-1)), std error of losses from NF (um^(-1)).

The measured and simulated dispersion are given in a .dat file with 12 columns: simulated propagation wavevector (pi/a), simulated higher order mode (eV), simulated propagation wavevector (pi/a), light cone (eV), measured propagation wavevector (pi/a), laser excitation energy (eV), simulated propagation wavevector (pi/a), simulated fundamental mode (eV), simulated propagation wavevector (pi/a), simulated slab modes (eV), quantum dots emission (photoelectrons/s), quantum dots emission energy (eV). The simulation code is given in a txt file, and it is intended for use with the freely available electromagnetic modelling software "MEEP" (https://meep.readthedocs.io/en/latest/). Information about how to run the script from command line is given in the txt file README.txt.

Near-field and far-field images are given in ASCII matrices.

Near field

Left: matrix of 191x299 pixels. x axis calibration: P1*x+P2, P1=0.089 um/pixel, P2=-8.5 um, initial pixel x=0; y axis calibration: P1*x+P2, P1=0.089 um/pixel, P2=-12.0805 um. The corresponding line profile is taken as the difference of a cut between x1=-0.5 um and x2=0.5 um and one between x3=2 um and x4=4 um. The data are given in ASCII file of 4 columns. In order: measured intensity (normalised units), measured position (um), intensity from fit (normalised units), position from fit (um).

Centre: matrix of 191x303 pixels. x axis calibration: as near field left, with P2=-9 um; y axis calibration: as near-field left. The corresponding line profile is taken as in Left. The data are given in ASCII file of 4 columns. In order: measured intensity (normalised units), measured position (um), intensity from fit (normalised units), position from fit (um).

Right: matrix of 191x298 pixels. x axis calibration: as near field left, with P2=-8.7um; y axis calibration: as near-field left. The corresponding line profile is taken as in Left. The data are given in ASCII file of 4 columns. In order: measured intensity (normalised units), measured position (um), intensity from fit (normalised units), position from fit (um).

Far field

Left: matrix of 254x254 pixels. x axis scaling: P1*x+P2, with P1=6.33634409E-5 nm^(-1)/pixel, P2=-2.30642930E-2 nm^(-1), initial pixel = 237; y axis scaling: P1*x+P2, with P1=6.33634409E-5 nm^(-1)/pixel, P2=-1.81219447E-2 nm^(-1), initial pixel = 159. The corresponding line profile is taken as a cut between -0.03 2pi/a and 0.03 2pi/a. The data are given in ASCII file of 4 columns. In order: measured intensity (normalised units), measured propagation wavector (2pi/a), intensity from fit (normalised units), propagation wavevector from fit (2pi/a).

Centre: matrix of 250x250 pixels. x axis scaling: P1*x+P2, with P1=6.40214639E-5 nm^(-1)/pixel, P2=-2.33038142E-2 nm^(-1), initial pixel = 239; y axis scaling: P1*x+P2, with P1=6.40214639E-5 nm^(-1)/pixel, P2=-1.83101390E-2 nm^(-1), initial pixel = 161. The corresponding line profile is taken as a cut between -0.03 2pi/a and 0.03 2pi/a. The data are given in ASCII file of 4 columns. In order: measured intensity (normalised units), measured propagation wavector (2pi/a), intensity from fit (normalised units), propagation wavevector from fit (2pi/a).

Right: matrix of 214x214 pixels. x axis scaling: P1*x+P2, with P1=7.52513879E-5 nm^(-1)/pixel, P2=-2.76925098E-2 nm^(-1), initial pixel = 261; y axis scaling: P1*x+P2, with P1=7.52513879E-5 nm^(-1)/pixel, P2=-2.13713944E-2 nm^(-1), initial pixel = 177. The corresponding line profile is taken as a cut between -0.03 2pi/a and 0.03 2pi/a. The data are given in ASCII file of 4 columns. In order: measured intensity (normalised units), measured propagation wavector (2pi/a), intensity from fit (normalised units), propagation wavevector from fit (2pi/a).

Research results based upon these data are published at https://doi.org/10.1117/12.2510478

## Funding

### Controlled long-range coherent coupling of solid-state qubits

Engineering and Physical Sciences Research Council

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