Patent ID: 8588570

Claim:
An apparatus comprising: a waveguide formed on a silicon-on-insulator (SOI) substrate; a p-doped region on a first side of the waveguide; an n-doped region on an opposite side of the waveguide, wherein when the p-doped region and the n-doped region are reversed biased optical power in the waveguide is monitored by measuring a two-photon absorption (TPA) generated current; a plurality of probe contact pairs on the top surface of the substrate straddling the waveguide, one of the probe contacts in each pair electrically connected to the p-doped region and the other of the probe contacts in each pair electrically connected to the n-doped region, the probe contact pairs being positioned at any point along the waveguide to enable the in-situ determination of the optical power traveling in the waveguide at that point.