US Patent 9904016 Wafer prober for testing in-wafer photonic integrated circuits

The invention relates to a wafer prober including an optical waveguide, the optical waveguide having a first optical coupling end segment with a first optical coupling surface being devoid of cladding. The first optical coupling end segment being configured to provide an adiabatic optical coupling to a second optical coupling end segment of a second optical waveguide of a photonic integrated circuit on a semiconductor wafer when the optical waveguide is aligned with respect to the semiconductor wafer according to a set of alignment requirements. The second optical coupling end segment having a second optical coupling surface that is devoid of cladding. The second optical coupling surface is parallel to a wafer surface of the semiconductor wafer. An alignment system configured to align the optical waveguide with respect to the semiconductor wafer according to the set of alignment requirements.