A Biochemical Sensor Based on a Sensing Waveguide With Efficient Analyte Overlap and a Single-Mode DFB Laser

A biochemical sensor based on the combination of a complex coupled distributed feedback laser with a sensing waveguide is presented. The sensing waveguide was realized by etching a deep trench into the middle of a ridge waveguide to increase the analyte overlap. These devices were investigated with respect to their sensitivity to refractive index changes of a surrounding analyte. A wavelength shift of about 12 nm was observed applying an index change of
$\Delta n= {{0.48}}$
. The analyte overlap was calculated to be 5.6%. Using this kind of monolithic, active, and single-frequency device could be an easy approach to sensitive affinity arrays.