Hybrid waveguide-bulk multi-path interferometer with switchable   amplitude and phase
  We design and realise a hybrid interferometer consisting of three paths based on integrated as well as on bulk optical components. This hybrid construction offers a good compromise between stability and footprint on one side and means of intervention on the other. As experimentally verified by the absence of higher-order interferences, amplitude and phase can be manipulated in all paths independently. In conjunction with single photons, the setup can, therefore, be applied for fundamental investigations on quantum mechanics. 
Robert Keil, Thomas Kaufmann, Thomas Kauten, Sebastian Gstir,   Christoph Dittel, Ren\'e Heilmann, Alexander Szameit, Gregor...
physics.optics