Ellipsoidal reflectors have two conjugate foci. Light from one focus passes through the other, after reflection. Ellipsoids collect a much higher fraction of total emitted light than a spherical mirror. Because ellipsoidal reflectors can enhance light collection without dramatically increasing heat in the illumination plane, they are an ideal selection for many projection and general illumination applications.

Off-axis ellipsoidal mirror with focuses F1=25 mm, F2=80 mm

In FTIR equipment they are used for focusing the radiation onto the detector. The diameter of the ellipsoidal mirrors is 42 mm and effective focal lengths of approximately 25, 80 and 160 mm.

Ellipsoidal reflectors have two conjugate foci. Light from one focus passes through the other, after reflection. Ellipsoids collect a much higher fraction of total emitted light than a spherical mirror. Because ellipsoidal reflectors can enhance light collection without dramatically increasing heat in the illumination plane, they are an ideal selection for many projection and general illumination applications.

Off-axis ellipsoidal mirror with focuses F1=25 mm, F2=160 mm

Parabolic reflectors and ellipsoidal reflectors are placed at a specified distance from the point to which an incident bundle of parallel light rays will converge. Primary length is determined as the length from the center of the reflector to the point where reflected collimated light converges for parabolic reflectors. When working with elliptical reflectors this measurement is determined as the distance of the light source from the reflector. A secondary focal length determination is also needed for proper focusing of ellipsoidal reflectors. This range is the point at which the reflected light converges outside the reflector.

Available are following off-axis ellipsoidal mirrors: