How lasers are going to work for you


Another Modern Mechanix moment here on Blah, Blah, Blahg. I’ve gotten hooked on this site, and find great articles from days past that are interesting to me. This latest is a 1970 Popular Science article reproduced for your edification.

The light fantastic is no longer a scientific curiosity: It’s now being used for just about everything from moon measuring to tire checking

By C. P. GILMORE / PS Consulting Editor, Science

. . .

Modern use of lasers

Today, lasers are working for you in ways you may have never suspected. For example, they’re . . .

  • Guiding tunnel and trench diggers
  • Welding microcircuits
  • Drilling holes in rubber nipples for baby bottles
  • Spotting tire defects
  • Machining parts to ultra-fine tolerances
  • Helping predict earthquakes.

How lasers work

Naturally, this last line is followed by a write-up of how lasers actually work.  The explanation might have been fairly technical at the time, but now it seems a little primitive.  Or maybe I just know more about lasers than I realized.  Regardless, the article continues:

First lasers

The laser first appeared as a glint in the eyes of physicists Charles Townes and Arthur Schawlow. In 1958 they wrote a paper saying that it should be possible to build a device in which photons, individual packages of light, could be used to stimulate excited molecules to give off yet more photons in step with the original ones. In 1960, physicist Theodore Maiman, then of Hughes, built one. Despite the high-powered physics that led up to its design, it was a deceptively simple device—a rectangular chunk of ruby surrounded by a bright photo-flash lamp. Every time the lamp flashed, its photons jiggled certain atoms in the ruby, causing them to give off photons and stimulate yet other atoms to radiate, just the way Schawlow and Townes said it would happen.

The new device was called a LASER—which stood for Light Amplification by Simulated Emission of Radiation. Since then, other investigators have made hundreds of liquids, solids, and gases lase, giving off hundreds of different wavelengths or colors of visible light, and hundreds of other wavelengths of invisible infrared and ultraviolet. Some generate power continuously, others in bursts or pulses.

Because laser light is coherent, it can be focused to an extremely small spot. The energy density of such a spot can be a billion watts per square centimeter or more—enough to vaporize any substance in existence.

Whoa.  That’s a lot of power in a single square centimeter.  I believe that’s even more concentrated death power than the Solar Death Ray!  After all this, there is a lot of information on potential practical uses for lasers – Military uses, highly accurate measurements, photo manipulation (particularly clearing up fuzzy images), and so on.  One of the most interesting to me is for large TVs.

Television. Another promising area: big-screen color TV. The current color TV tube has about reached its limit. And that three-color dot system doesn’t produce the sharpest pictures. A much better TV system could be built using three laser beams—red, blue, and green—projected on a screen. The screen could be any size—it could cover a living-room wall or the end of a theatre.

At least two such systems have been built. General Telephone and Electronics has demonstrated a four-foot-wide TV picture. And now, at Expo 70 in Japan, Hitachi has on display a system with a picture 9 by 12 feet. People who have seen it say the picture is more brilliant and lifelike than the one we see on regular color TV sets.

Ultimately, such wall-to-wall TV may be practical in our homes. But right now, there’s a problem. Most lasers are highly inefficient. The big-screen laser display in Japan uses three lasers, each putting out about 7 watts of power. But it takes 30 kilowatts to run the equipment—too much for use in the home.

They had me right up to 30 kilowatts.  I don’t think my wife would let me run  a 30 kilowatt TV in our house.  Of course, think of the reduction in heating costs for the winter when such a beast was running!  Anyway, I think this concept of large televisions in the home is worth pursuing.  Someday it might be nice to have a screen large enough to function as a home theatre…
Sadly, nowhere in the article is there any guidance on how to mount these technological wonders on the heads of frikkin’ sharks for offensive use – I really thought such an idea would have been covered under the military research section.  Although maybe that information is classified.

[tags]Modern Mechanix, Lasers, Frikkin’ Sharks[/tags]