Newton’s lab notebook showing his study of the
refraction of light (ca. 1672).
OPTICS IN 2D
Optics in 2D
you’ll trace light rays (in two dimensions) through optical media using a single-ray
or a multi-ray projector. In this manner the basic laws governing the refraction and focusing of light may
be deduced. In
Optics in 3D
an optical bench will be used to study the
of real lenses which,
of course, are used to focus light in three dimensions. It is ﬁrst easier, however, to work with individual,
We will begin this lab by studying what happens when a beam of light is incident on a piece of material.
First, we will study the refracted light that travels through the material, and test Snell’s law (Section 4),
which tells us how much a particular beam will be refracted. Next, we will ﬁnd that the light reﬂected from
the material has interesting polarization properties, looking in particular at Brewster’s angle (Section 5).
In Section 6, we will observe the phenomena of total internal reﬂection, which can occur in some optical
media. We will then examine lenses, both converging (Section 8) and diverging (Section 9).
By the end of this lab, you should know what is meant by the “index of refraction” of a material and
how to use Snell’s Law to relate the angle of incidence to the angle of refraction. You should know what a
focal plane is and how to ﬁnd it for converging and diverging lenses and mirrors, both experimentally and
by calculating from the shape using the lensmaker’s equation. You should know what kinds of aberration
may be present and in what cases they appear.
starting this lab, you should be familiar with the following physical concepts. If you need to
review them, or if you haven’t yet discussed them in your lecture course, consult the indicated section in
McKay, Physics 235 Coursepack Lecture Notes.
Snell’s law and the index of refraction, §26.1-2
Total internal reﬂection, §26.3
Dispersion of light and prisms, §26.5
Lenses and image formation, §26.7-8
Polarized light, §24.6