Planar achromatic multiple beam splitter by adiabatic light transfer

We introduce a novel achromatic and robust scheme for n-fold multiple beam splitting based on adiabatic light transfer in a planar geometry of coupled waveguides (WGs). The concept is experimentally verified for a one-to-three beam splitter by using a reconfigurable light-induced WG structure at two operating wavelengths. The demonstrated planar-type achromatic beam splitter opens new opportunities for the realization of ultra-high bandwidth on-chip photonic devices.