Strategies for successful realization of strong confinement microphotonic devices

Abstract

Microphotonic devices employing strong confinement of light are of growing importance for key applications such as telecommunication and optical interconnects. They have unique and desirable characteristics but their extreme sensitivity to dimensional variations makes them difficult to successfully implement. Here, we discuss strategies towards the successful realization of strong confinement devices. We leverage what planar fabrication technology does best: replicating structures. Although the absolute dimensional control required for successful fabrication of many strong confinement devices is all but impossible to achieve, we show that surprisingly-high relative dimensional accuracy can be obtained on structures in proximity of one another on a wafer. This provides an advantage to schemes that are based on multiple copies of low-complexity structures. These copies can be made nearly identical or with precise relative-dimensional offsets to achieve the desired function. We quantify the achievable relative dimensional control and discuss the first demonstration of multistage filters, integrated polarization diversity, and high-order microring-filter banks.