Patent attributes
The optical design of a measurement system is disclosed. The measurement system comprising a light source configured to provide light along a first axis. The measurement system has a reflecting lens aligned along a second axis where the reflecting lens has a first focus on the second axis and a second focus on the second axis where the second focus is between the first focus and the reflecting lens and where the second focus is positioned near the first axis. The measurement system has a field lens located on the second axis and positioned such that the second focus of the reflecting lens occurs inside the field lens. The measurement system has a relay lens system aligned to the second axis where the relay lens system forms a first focus at the second focus of the reflecting lens. The measurement system has a sensor located on the second axis at a second focus of the relay lens system and is configured to detect scattered light near the second focus of the reflecting lens.