docs: def SingleModeCombine(pupils,modeDiameter=None):
      """
      Return the instantaneous coherent fluxes and photometric fluxes for a
      multiway single-mode fibre combiner
      """
      if modeDiameter is None:
          modeDiameter=0.9*pupils.shape[-1]
      amplitudes=FibreCouple(pupils,modeDiameter)
      cc=np.conj(amplitudes)
      fluxes=(amplitudes*cc).real
      coherentFluxes=[amplitudes[i]*cc[j]
                      for i in range(1,len(amplitudes))
                      for j in range(i)]
      return fluxes,coherentFluxes