Lasers have been around since the fifties, but not where
most people could see them. The early lasers were large, expensive, delicate
machines. They could only be afforded by governments, industry, and the
occasional university. They tended to be experimental devices, but some
practical uses were soon found for them. The military used them, not as
death rays, but as a means to mark targets, and measure their range. Industry
used them for quality control, to measure the trueness or flatness of a
surface, and for stress testing, and non-destructive testing.
Though most people associate lasers with Flash Gordon,
and the "death ray" of pulp science fiction fame, few lasers of such power
existed before the late sixties/early seventies, and they did not become
anything like common, before the eighties. These tend to be built around
carbon dioxide lasers, and require high capacity cooling units, when used
in continuos duty industrial applications. These types of lasers are generally
employed on mechanical arms, and can be used as welders, cutters, or for
etching and burning. They tend to be integrated into computer controlled
productions stations, and are rarely under the direct control of a human
operator. Though associated with heavy indistry, cutting lasers are beginning
to find use in the production of lighter goods, such as clothing. They
are also used to etch designs into everything from bowling trophies, to
firearms. Smaller, less expensive versions of these machines are beginning
to make their way down to the level of the small business, or even the
hobbyist.
I vividly recall the early days of the consumer
laser. This seemed to start around the early seventies, and was in full
swing by the eighties. My first actual experience with a laser was in the
early seventies, when a laser demonstration was given at school. A helium
neon, tube type laser was demonstrated for us, in the auditorium. It generated
the, now familiar, red spot on the wall. Like most lasers of the time,
this was a low powered unit, putting out perhaps 1-5 mw. Like most units
of the day, it took the form of an oblong box, a bit over two feet long,
and maybe six inches on a side. It was plugged into an external power supply,
and was quite an impressive contraption, in the darkened school auditorium.
These early experimenter, and hobbyist units were available from outfits
like Edmund Scientific, and sold for the $300-$1000 range. This was a fair
amount of money back in the early seventies.
These early lasers, as neat as they were, did have
their problems, however. Like the first generation of experimental units,
they were heavy, expensive, delicate, and could be a little sensitive,
and temperamental. Still, this was the first chance for a consumer to get
his hands on an actual functioning laser. Besides the novelty aspect, these
early consumer grade units gave users access to holography, experiments
in laser communications, and light shows.
The key and distinctive word used to describe the
quality of laser light is "coherent". This is a rather strange word to
use, in relation to something like light. The literal meaning of coherent
is orderly, or intelligible. The word is used, because there is no other
word which, singly, comes close to being a description of what laser light
is. In a laser beam, all light emitted is oriented in the same direction,
and has the same phase. This gives a beam of startlingly integrity, and
conformity.
The first laser I ever owned was a laser gun sight,
for my Calico pistol. I bought the sight in the mid nineties, at a gun
show, and was quite pleased with myself. Within a couple of years, I had
several of the cheap laser diode units, commonly sold as pointers. I eventually
had to have a tube type laser, for the superior convergence of the beam,
and finally decided that I needed a high powered, industrial type laser.
I also own several multimedia converters, for connecting computers via
a fiber optic link. These contain a laser as a sending beam. There is no
distinction, these days, to owning laser devices; nearly everyone owns
several. They have become simply another electronic component. We have
them in our computers, our CD and DVD players. In the meantime, as their
size and price goes down, more uses will doubtless be found for them.