Label-free lab-on-chip biosensor based on photonic a-Si:H resonators Photonic systems based on crystalline silicon have been the subject of intensive research since the 1980s [1, 2]. The most well-known application is data transmission in the telecommunications sector, but integrated photonic systems also offer great potential for sensor systems, including the subject of this paper, possible biotechnological and medical applications. The high demands put on measurement technology in relation to the low detection limits of various chemical and biological substances, as well as high sensitivity and selectivity of the application environment, make the challenge of bringing a viable sensor to market very difficult. A new sensor needs to be CMOS compatible and flexible in terms of front-end and back-end compatibility. Photonic resonators made of amorphous silicon (a-Si: H) with chemically modified surfaces provide a suitable platform. Materials with high refractive index differences with small feature sizes combined with microfluidic systems for real-time measurement systems can be adapted for such uses. The unique form of a microring resonator, as shown in the following example, shows a higher interaction length for measurement than the actual physical size of the resonators itself.
