Patent attributes
A light combiner (500) for use in a metrology tool includes a plurality of light sources (LED 1, LED 2, LED 3, LED 4, LED 5), a first filter (502), and a second filter (504). The first filter is designed to substantially reflect light generated from a first source of the plurality of light sources, and to substantially transmit light generated from a second source of the plurality of light sources. The second filter is designed to substantially reflect light generated from the first source and the second source of the plurality of light sources, and to substantially transmit light generated from a third source of the plurality of light sources. An angle of incidence of the light generated from the first source on a surface of the first filter is less than 30 degrees.