ILLUMINATION OPTICS: Kohler integration optics improve illumination homogeneity

摘要

Formed by a combination of reflective and/or refractive surfaces and organized in corresponding pairs, a Kohler integrator can be superimposed onto designed optical surfaces to improve optical-system performance of light-emitting-diode-based illuminators. Abbe and Kohler illumination are standard methods used to provide uniform illumination on a target. Abbe illumination works well only if the source itself has uniform irradiance. Typical sources like incandescent filaments, discharge lamps, and light-emitting diodes (LEDs) do not meet this criterion. In Kohler illumination, each point at the target area is illuminated by the entire source so that irradiance variations across the source do not affect the target illumination (see www.laserfocusworld.com/articles/349360).