  The Planet Formation Imager (PFI) initiative aims at developing the next
generation large scale facility for imaging astronomical optical interferometry
operating in the mid-infrared. Here we report on the progress of the Planet
Formation Imager Technical Working Group on the beam-combination instruments.
We will discuss various available options for the science and fringe-tracker
beam combination instruments, ranging from direct imaging, to non-redundant
fiber arrays, to integrated optics solutions. Besides considering basic
characteristics of the schemes, we will investigate the maturity of the
available technological platforms at near- and mid-infrared wavelengths.
