Grade 10 Academic Science – Optics
Laser Wars
The word LASER is the acronym for Light Amplification by Stimulated Emission of Radiation.
A laser is a special source
of light of only one pure
colour (or WAVELENGTH)
or monochromatic. You
cannot break up laser light
into other colours.
Moreover, a laser is an
optical light source that
emits a concentrated beam
of photons. The beam
stays together. Thus, the
beam stays together over a
long distance and can be
focused on a very small
spot.
Diffract the Laser
A laser is only one wavelength of colour; yet, it is still a very narrow beam of many rays. Can the
rays be diffracted (i.e., eliminate or alter part of the beam)? If you shine the laser through a fine
mesh or a bird's feather and onto a white wall, you may be able to create interesting patterns. A
laser beam can be described as an array of almost perfectly synchronized waves. When you split
the beams, you interfere with that synchronization. As a result, some waves will reinforce each
other and some will neutralize each other waves. This action creates mesmerizing geometrical
patterns.
Aim your laser at a frosted incandescent light bulb. The bulb will glow and have several internal
reflections.
How do your polarized sunglasses work?
Using two polarized sunglass lenses (…just use two pairs of sunglasses), place both lenses in
the laser beam. Rotate one sunglass 90O. The lenses should block the light completely in one
configuration and allow it to pass-through the other way.
Laser Maze
Work your laser beam around a maze using mirrors and lenses.
INTERESTING TIDBIT
A new light tool called "driver defeat or Laser Dazzler" is being developed to help soldiers slow
approaching cars from a distance so they can determine if the driver is friend or foe. It works
using laser. When a laser is pointed at the eye, the flashes create an "after-image," an optical
illusion that limits a person's sight for a very short time. It' will be a little like driving into the sun.
That is, a driver’s natural reaction while driving and experiencing glare is to either slow down or
stop (source National Defense Education Program. http://www.ndep.us/laser-dazzlers ). Who
would have thought -- lol.