Microwave photonic phase shifter based on the integration of ITO-enabled microheaters

Abstract

The advances in reconfigurable microwave photonic (MWP) integrated devices calls for the discovery of materials that can offer the same reconfigurable properties. In this paper, we explore the use of indium tin oxide (ITO), which belongs to the family of transparent conductive oxides (TCO), for the first demonstration of tunable on-chip MWP devices. The ability to modify the optical and electronic properties of ITO makes this a novel material with unlimited possibilities to outperform current tunability mechanism. In this paper, we demonstrate the use of the quasi-metallic feature of ITO as an active microheater control for realizing a tunable MWP phase shifter. Experimental results show the successful tuning of the RF phase shifts from 0 – 322°, almost across the full phase tuning range of the single ring, throughout a 20 GHz span by driving the ITO microheaters with a biased voltage tuned from 1.05 V to 5.25 V.