3B Scientific Laser Optics Supplemental Set - Manual (Page 13)

28
E20b Light beam passing through air concave lens
– the rays are non-parallel to the optical axis
(U17301)
The plane
ϕ
' which is perpendicular to the optical axis,
combined with figure focus F' is called a figure focus
plane. If a beam of perpendicular rays impinges the
concave air lens, the rays cross the plane
ϕ
' at one point.
E21a Parameters of thick lenses – determination
of radius of curvature
(U17300/U17301)
The lenses in the set have cylindrical refraction sur-
faces with circular bottoms with equal radia of curva-
ture. You can measure these radii by using a milimetre
grid.
E21b Parameters of thick lenses – focal length
(U17300/U17301)
In the case of a thick lens (a lens with not negligible
thickness) the definition of the focal length as a dis-
tance of the focus from the main planes (points – H
and H'), must be taken into account.
E22a Model of a normal eye
(U17300, transparency A)
Display rays parallel to the optical axis intersect after
passing through uncorrected eye lens at one point of
the retina.
Place the eye lens (1) directly behind the line O
2
.
Acrylic
Acrylic
Retina
Eye lens
Air Air