Mid-infrared integrated photonics on silicon: a perspective

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. Keywords: mid-IR; integrated photonics; silicon photonics; spectrometer; optical sensorUnited States. National Nuclear Security Administration (Grant DE-NA0002509)United States. Defense Threat Reduction Agency (Grant HDTRA1-13-1-0001)National Science Foundation (U.S.) (Award 1453218)National Science Foundation (U.S.) (Award 1506605)National Natural Science Foundation (China) (Grant 61475129