MEMS-Enabled On-Chip Computational Mid-Infrared Spectrometer Using Silicon Photonics

Abstract

On-chip spectrometers using silicon photonics offer a compact, energy-efficient, and cost-effective solution to biochemical spectroscopy and hyperspectral imaging in integrated and portable application scenarios. The mid-infrared (MIR) spectral band is critical to spectroscopic sensing. However, the existing on-chip spectrometer approaches are limited in the MIR. Here, we present an on-chip computational spectrometer in MIR (3.7–4.05 μm) using an MEMS-enabled silicon photonic integrated device, which is realized via the time-domain modulation of reconfigurable waveguide couplers. The electrostatically actuated on-chip spectrometer intrinsically features low power consumption and single-pixel detection and offers multiplexing advantages, potentially leading to a high signal-to-noise ratio. We achieve laser spectrum reconstruction across a large bandwidth (350 nm) experimentally. Furthermore, based on a linear superposition assumption, we achieve the polychromatic light reconstruction of narrow spectral features (3 nm resolution) and a broad absorption spectrum of nitrous oxide gas using a regularized regression method.

Machine learning-augmented surface-enhanced spectroscopy toward next-generation molecular diagnostics

“…73–85 The nanofabrication technologies for preparing SEIRA/SERS substrates include chemical preparation methods, photolithography, electron beam lithography, magnetron sputtering, electron beam evaporation, and more. 86–107 The widely used theory for modeling SERS/SEIRA includes perturbation theory, 108 temporal coupled-mode theory, 109,110 coupled harmonic oscillator theory, 111 and so on. As mentioned earlier, machine learning is complementary to SERS/SEIRA and offers unparalleled possibilities for solving pressing challenges related to spectral artifacts, overlapping, and huge volumes of spectral data (Fig.…”

Emerging Wearable Chemical Sensors Enabling Advanced Integrated Systems toward Personalized and Preventive Medicine

“…In 2022, Qiao closer to the chip-scale integration for the mid-IR sensing platform. 186 As illustrated in Figure 6e, the on-chip computational spectrometer consists of a pair of simple MEMS tunable suspended waveguide couplers. The effective tuning of waveguide couplers was enabled by electrostatic actuation, and the spectra were acquired via the time-domain actuation of the couplers.…”

“…(e) Miniaturized spectrometer for VOC sensing. Reproduced from Qiao, Q.; Liu, X.; Ren, Z.; Dong, B.; Xia, J.; Sun, H.; Lee, C.; Zhou, G. ACS Photonics 2022 , 9 , 2367–2377 (ref ). Copyright 2022 American Chemical Society.…”

“…One of the ultimate goals of wearable waveguide technology is to construct on-chip spectrometers for a compact, energy-efficient, and cost-effective solution to biochemical spectroscopy. In 2022, Qiao et al presented an on-chip spectrometer using Si photonics, pushing one step closer to the chip-scale integration for the mid-IR sensing platform . As illustrated in Figure e, the on-chip computational spectrometer consists of a pair of simple MEMS tunable suspended waveguide couplers.…”

Midinfrared Spectroscopic Analysis of Aqueous Mixtures Using Artificial-Intelligence-Enhanced Metamaterial Waveguide Sensing Platform

“…Meanwhile, wastewater monitoring, as one crucial aspect in industry 4.0, and the demand for various types of miniaturized sensors, such as chem/biosensors for in situ and real-time monitoring of wastewater quality, are ever-increasing. Over the years, chem/biosensors have grown rapidly along with the variety of sensing mechanisms being developed, such as electrochemistry sensors, mechanical sensors, and optical sensors. − Among these, nanophotonic waveguides provide a cost-effective solution for miniaturized sensor applications due to the high compactness and versatility from the increasing levels of integration, − which also benefits other photonic devices, such as the nanophotonic waveguide-based spectrometer. − …”