Deterministic integrated tuning of multi-cavity resonances and phase for slow-light in coupled photonic crystal cavities

TL;DR

This paper demonstrates precise, integrated tuning of multiple photonic crystal cavities on a chip, enabling control over resonances and phase for advanced slow-light and filtering applications.

Contribution

It introduces a deterministic, chip-scale tuning method for multiple coupled photonic crystal cavities with high precision and preserved quality factors.

Findings

Resonance tuning efficiency of ~1.60 nm/mW

Inter-cavity phase tuning of ~0.038 pi/mW

Switching between EIT and flat-top filter lineshapes

Abstract

We present the integrated chip-scale tuning of multiple photonic crystal cavities. The optimized implementation allows effective and precise tuning of multiple cavity resonances (up to ~1.60 nm/mW) and inter-cavity phase (~ 0.038 pi/mW) by direct local temperature tuning on silicon nanomembranes. Through designing the serpentine metal electrodes and careful electron-beam alignment to avoid cavity mode overlap, the coupled photonic crystal L3 cavities preserve their high quality factors. The deterministic resonance and phase control enables switching between the all-optical analogue of electromagnetically-induced-transparency (EIT) to flat-top filter lineshapes, with future applications of trapping photons/photonic transistors and optoelectronic modulators.