Experimental study of broadband unidirectional splitting in photonic crystal gratings with broken structural symmetry

It is experimentally demonstrated that the combination of diode and splitter functions can be realized in one broadband reciprocal device. The suggested performance is based on the dielectric photonic crystal grating whose structural symmetry is broken owing to non-deep corrugations placed at one of the two interfaces. The study has been performed at a normally incident beam-type illumination obtained from a microwave horn antenna. The two unidirectionally transmitted, deflected beams can show large magnitude and high contrast, while the angular distance between their maxima is 90 degrees and larger. The dual-band unidirectional splitting is possible when using TM and TE polarizations. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4800147]