Backside light irradiation through a transparent stage avoids wiring-layer interference, improving defect sensitivity and reducing wafer dead space.
Optical imaging feedback and actuated positioning keep probe-to-DUT gap spacing and orientation stable for micrometer-level optical testing.
Multiple optical paths at different vertical levels let one fixture test varied optoelectronic IC designs without separate custom setups.
Separate optical and electrical assemblies create alignment issues; an integrated probe enables simultaneous wafer-level testing.