Germanium-on-silicon nitride (GON) is a novel platform fabricated by wafer bonding and layer transfer. It has a larger refractive index contrast and a wide transparency range in mid-IR making compact waveguide sensors feasible. By applying mid-IR light source as the probing wavelength, it provides a simple but effective sensing mechanism as many molecules have their strong and particular absorption peaks in mid-IR. By choosing proper probing wavelength and monitoring the power drop at the output end of the waveguide sensor, it will be simple and effective to identify and quantify the substances in gas or liquid phase surrounding the waveguide sensors.
The sensor on GON platform is small in size and with high sensitivity. It provides simple but effective sensing mechanism for target molecules detection and real time monitoring. A waveguide device, with the source wavelength range of 2 um to 3.8 um (getting into the Mid-IR range of 2 ~ 20 um), based on the proposed novel structure of Ge-on-SiN stack, has been demonstrated to generate: single mode transmission and low propagation loss and signal distortion.
Mid-IR sensing will have major impact on food processing, in addition to environment studies (e.g., detection of hazardous and greenhouse gases), industrial leak detection, process control, medical breath analysis, and many others.
It can be integrated with wearable and portable devices like sports bracelet, earphone, cellphone and many for health monitoring in real time, breath analysis, non-invasive blood test and so on. it can be integrated in food industry processing for real time monitoring of additives’ quality and quantity thus providing a fast, effective solution to detect all kind of materials whether they are expired or overdosed.
It can be integrated in wearable and portable devices to monitor people’s health condition in real time. It is small in size and cost effective and by using the mid-IR light as the probing source, it can be non-invasive detecting method for some diseases.