function positions = getSweepWavelengths(N, df_hz, StartNm)
    positions = zeros(1, N);
    for i = 1:N
        position = (299792458 / (299792458 / (StartNm * 1e-9) + (i - 1) * df_hz)) * 1e9;
        positions(i) = position;
    end
end