Mid-infrared integrated photonics on silicon: a perspective

TLDR

Silicon photonics has become the preferred substrate for integrated optics, yet most devices operate in the near‑IR, while the mid‑IR (2–20 µm) band offers a significant growth opportunity. This review presents the authors’ perspective on the emerging field of mid‑IR integrated photonics on silicon. The authors survey key mid‑IR photonic components—waveguides, light sources, modulators, and detectors—and analyze on‑chip spectroscopic chemical sensing as a system‑level example. Their quantitative analysis shows how component choices affect system performance and integration technologies for mid‑IR photonic sensing.

Abstract

Abstract The emergence of silicon photonics over the past two decades has established silicon as a preferred substrate platform for photonic integration. While most silicon-based photonic components have so far been realized in the near-infrared (near-IR) telecommunication bands, the mid-infrared (mid-IR, 2–20-μm wavelength) band presents a significant growth opportunity for integrated photonics. In this review, we offer our perspective on the burgeoning field of mid-IR integrated photonics on silicon. A comprehensive survey on the state-of-the-art of key photonic devices such as waveguides, light sources, modulators, and detectors is presented. Furthermore, on-chip spectroscopic chemical sensing is quantitatively analyzed as an example of mid-IR photonic system integration based on these basic building blocks, and the constituent component choices are discussed and contrasted in the context of system performance and integration technologies.