Ray Trace Applet
This applet traces paraxial light rays through a user-specified system of up to 12 ideal thin lenses and apertures, allowing many simple optical instruments to be modelled. Three examples are given: coupling of light from one instrument to another, a Newtonian telescope, and a projector.
The user can modify the optical system as desired by changes to the three parameters of each element:
As changes are made, new ray traces are performed by the applet. Elements
may be deleted or inserted by entering the appropriate element number in
the delete or insert boxes at the bottom of the screen. A lens may be changed
to an aperture by deleting its focal length field. If the first element
is given a negative distance, it is not shown on the ray trace (see the
telescope example). Two sets of rays can be displayed: the extreme rays
defined by the diameters of the first two elements, or a bundle of rays
coming from a single point on the object.
Thad G. Walker, University of Wisconsin-Madison, January 1998