Integrated device for polarization-independent electro-optic modulation using a splitter-rotator structure

Abstract

An integrated device for polarization-independent electro-optic (EO) modulation based on photonic crystal is proposed. It primarily consists of three components: a polarization splitter-rotator (PSR), a combiner, and a graphene EO modulator. In the PSR, the TE0 modes and TM0 modes achieve polarization splitting and mode conversion. Subsequently, the two TE0 modes pass through the combiner to merge into a single beam. Finally, the TE0 modes enter the modulator for EO modulation. The performance parameters of the integrated device are computed and analyzed using the three-dimensional finite-difference time-domain method. The results reveal that the integrated device achieves a polarization extinction ratio of 23 dB, an insertion loss of 0.3 dB, and an extinction ratio of 21.1 dB. The modulator has a driving voltage of 3.56 V and a modulation speed of 33 GHz. The integrated device is well-suited for application in large-capacity optical communication systems.