Planar optical waveguide technology (PLC) based on ion exchange in glass has recently been extended to multimode waveguide structures with large core diameter. Monolithic multimode planar waveguides are now commercially available in form of fiber coupled optical waveguide systems. Optical parameters of the waveguides can be tuned according to the corresponding fiber type over a wide range:

• numerical aperture (NA) up to 0,5
• geometrical waveguide cross section up to 500 µm
• spectral range from 400 to 2000 nm

First products include standard multimode splitters 1x2, 1x4, 1x8, 1x16 for QQ or PCF fibers with core diameters of 200µm and numerical apertures of 0.22 and 0.37, respectively. In addition, special custom designed waveguide structures with a core diameter of only 20µm have also been fabricated and show the spectrum of opportunities given by this technique. Fiber-chip coupling is realized analogous to single mode chips with fiber arrays, which LEONI offers in its product portfolio for Telecom networks since some years.
 
Besides setting up a complete product portfolio for standard multimode fibers, LEONI’s R&D team is also capable to develop short term customized prototypes. All steps of the production chain are performed by LEONI in Germany only.
 
Planar multimode waveguides are well suited for a variety of applications, especially where complex optical functionality needs to be integrated in a monolithic layout. Thus, compact functional elements with low insertion loss and low wavelength dependant losses can be designed for e.g. spectroscopy, medical science, optical power transfer, sensors, data and signal transfer and many others. Through their compact set-up they are easy to combine with lenses, filters and other micro-optical elements.