Compact and fast read-out for wavelength-encoded biosensors

Many established and recently-introduced optical biosensor concepts rely on the detection of a small wavelength change in response to change of temperature, adhesion of bio-particles, strain, or chemical environment. Special coatings are used to sensitize them to specifically bound molecules (e.g., biomarkers). We describe a compact and fast wavelength monitor that can resolve sub-pm wavelength changes. The unit was demonstrated by reading out a FBG sensor and can resolve wavelength changes as small as 50fm with a bandwidth of more than 100Hz.