In this article, an introduction to illumination systems is presented.
What is illumination system design?
In one sentence, illumination system design is the design act to transfer the light from a light source into the desired distribution.
It follows that, for all illumination systems, you must have a light source, and a method to characterize the output of the system.
Examples of illumination systems
Laser diodes
By 彭嘉傑 – Own work, CC BY 2.5, Link
Lenslet arrays
Backlight displays
Projector systems
Light guides
Paraboloidal and ellipsoidal reflectors
In both diagrams we can see that only a subset of the light emitted by the source will hit the mirror and be directed or focused in the intended manner. Light emitted from right to left (not shown) would miss the mirror in both examples, and be wasted in the optical system.
Reference Source: https://www.zemax.com/
