High uniformity splitter with great inhibition of ±1st orders

Abstract

A transmissive double-groove grating under vertical incidence is proposed in this paper. The grating has a total of five diffraction orders, and the effect of a three-channel beam splitter is achieved by inhibiting the diffraction efficiency of ±1st orders. This is a polarization-independent micro-nano structure that achieves triple beam splitting under both TE and TM polarization. The diffraction efficiency of the 0th order and ±2nd orders for TE polarization orders can reach 32.55% and 32.72%, respectively. And the diffraction efficiency of 0th order and ±2nd orders for TM polarization can reach 32.28% and 32.59%, respectively. Both TE and TM polarization can achieve 99% uniformity. The grating performs well in terms of manufacturing tolerances and immunity to interference.