A compact refractometric sensor based on grated silicon photonic wires

Grated silicon photonic wires for refractometric applications have been fabricated using a 248-nm deep UV lithography. It is shown experimentally, that a device with length of only 180 μm has an index sensitivity of 10−6 assuming a detector power resolution of 1%. It is also demonstrated that the device is suitable to monitor index changes in a liquid cladding, which could be used to monitor on chip chemical reactions.