Video Transcript
The diagram shows some apparatus used in holography, including a cylindrical
object. At which of the labeled components will a holographic image of an object be
recorded? (A) I, (B) II, (C) III, (D) IV, (E) VII.
In our diagram, we see our cylindrical object. This object is being illuminated by light that ultimately comes from this source, a
laser. The various components of this setup that allow us to form a holographic image of our
object are numbered. We see that number I corresponds to this part of the apparatus. Number II is here, number III is here, number IV is down here, and number VII, our
last answer option, is here. We want to know at which of these specific label components will the holographic
image of our object be recorded.
Once light leaves our laser, it travels to this second component, which is a beam
splitter. This beam splitter permits 50 percent of the light incident on it to pass right
through while reflecting the other 50 percent in this direction. The light that passed directly through the beam splitter follows this path until it
reaches a mirror. The mirror reflects this incoming light and sends it through a prism, labeled part
V. The prism spreads out the incoming light so that it covers the entire cylindrical
object. This light is then naturally reflected from the object and onto this last component,
component VII. That’s one of the two pathways that light travels in this apparatus.
The other pathway involves the light that was reflected from our beam splitter
downward. This light is then reflected off of a mirror, labeled component IV, and then also
pass through a prism, labeled component VI, so that it spreads out and covers the
entire component, labeled VII. We see then that our two separate pathways of light recombine at this final
component. Indeed, this is where an interference pattern of the incoming light is formed. That pattern recorded on a photographic plate allows us to create a holographic image
of our object.
We know then how we’ll answer this question. It’s at component VII in our apparatus, a light-sensitive, or photosensitive, plate
where a holographic image of our object of interest is recorded. We choose answer choice (E).
