For the first time, researchers have fabricated high-performance mid-infrared laser diodes directly on microelectronics-compatible silicon substrates. The new lasers could enable the widespread development of low-cost sensors for real-time, accurate environmental sensing for applications such as air pollution monitoring, food safety analysis, and detecting leaks in pipes.
Most optical chemical sensors are based on the interaction between the molecule of interest and mid-infrared light. Fabricating mid-infrared lasers on microelectronics-compatible silicon can greatly reduce their cost because they can be made using the same high-volume processing techniques used to make the silicon microelectronics that power cell phones and computers.
The research was conducted as part of a consortium, which is developing miniaturized, portable low-cost optical sensors for chemical detection in both gases and liquids. For this project, the researchers are working upstream by developing photonic devices for future sensors. At a later stage, these new mid-infrared lasers could be combined with silicon photonics components to create smart, integrated photonic sensors.