Sensitive Label-Free Biomolecular Detection Using Thin Silicon Waveguides
Figure 5
(a) Schematic of an MZI evanescent field sensor. The input waveguide is split into two paths where one is exposed to the analyte and the other is isolated from the analyte. The paths are recombined and the signals interfere causing a sinusoidal phase dependent intensity signal to be transmitted through the output waveguide. (b) A conventional ring resonator design employing a directional coupler between the straight bus waveguide and the ring cavity. The dashed lines indicate the positions of the sensor windows where the upper SU-8 isolation layer is removed.
