US Patent 7957066 Split field inspection system using small catadioptric objectives

A system for inspecting a specimen is provided. The system includes an illumination subsystem configured to produce a plurality of channels of light energy, each channel of light energy produced having differing characteristics (type, wavelength, etc.) from at least one other channel of light energy. Optics are configured to receive the plurality of channels of light energy and combine them into a spatially separated combined light energy beam and direct it toward the specimen. A data acquisition subsystem comprising at least one detector is provided, configured to separate reflected light energy into a plurality of received channels corresponding to the plurality of channels of light energy and detect the received channels.