The Scary Red Laser Spotlight

The Scary Red Laser

By Charles Harmon

Sometime back in the late 60s on my first job after getting my AA Degree at Pasadena City College (California) I was working with an engineering company. It was a small company in Pasadena which was digitizing maps for oil companies. I was the digitizer and operated a drafting board instrumented with sensors that allowed me to trace squiggles on a large long map, sometimes 10 feet or longer. The digitized data from the maps were used to locate oil underground.

It was an interesting, but boring job. What I really liked was being able to use the fast IBM computer a couple of hundred feet down the street to run the computer programs that analyzed the digitized data and determined where the oil was located. I thought the programs that Pat, their programmer wrote, were really cool to be able to figure out where the oil was by using virtually all mathematics to recreate another map that almost plainly showed the pockets of oil.

But most of all I enjoyed being able to talk to the young PhD engineers where I worked who were using lasers. Lasers were relatively new and were really being exploited commercially on a large scale and by schools in their labs. As we discussed properties of lasers and uses for them it was suggested an experiment be done to see if one of their gas lasers could be seen far away. Also they wanted to know how wide the beam might be at a distance.

So one evening just before the sun started going down I and a couple of the engineers decided to take a ride to a “lover’s lane” up the road leading to the mountains above Pasadena. From the location of the building where we worked we calculated it was about 7.5 air miles to the spot in the lover’s lane lookout point above La Canada and Pasadena.

When we finally got there it was dark, but you could see the lights of the city below and the last vestiges of daylight. We hoped the laser was aimed correctly because there were trees and bushes, along with parts of the hill all around.

There were a few cars parked and some necking going on inside, like you see in the movies. We weren’t interested in that, but headed for a clearing where we hoped the laser beam might possibly be seen. We didn’t know what to expect or if we would even be able to see such a weak 50 milliwatt red laser beam.

As I walked into the clearing where the laser was pointed some seven plus miles away I noticed a weak red light in the distance. As I walked further the light got brighter and brighter. In the center of the beam, it was the laser beam shinning directly at us, it was very bright. It was like a big red scary spotlight. In fact it was brighter, by far, than all of the lights you could see in Pasadena and the few surrounding little cities.

We were all surprised. The beam not only could be seen, but it was very bright. It’s hard to describe how bright that little laser beam was, but roughly you could say it was about as bright as a setting sun on the horizon. You could see no light from the side of the beam, only if you were directly in 10 – 15 feet center of the beam.

What was also somewhat surprising was the beam width was only about maybe 15 or so feet across. Once you walked past that the light dropped off very rapidly. Even some twenty to twenty-five feet from the center there was no beam and it was almost impossible to see the now pinpoint of light emanating from the laser.

The couples in the cars were looking at us and wondering what the commotion was about. I doubt any of them could see the laser beam from their positions. We stayed there a few minutes amazed at the brightness and narrowness of that little laser. I wondered how much brighter a more powerful laser would be or one that had lenses to focus the beam into a smaller beam width.

Ever since that time I have been interested in lasers and have had one for at least 30 years. Since then I wanted to see a powerful x-ray laser or gamma ray laser or one that could pierce metal from a long distance. Well there are x-ray lasers now, but I don’t think gamma ray lasers have been created yet (I could be wrong) although studies and experiments are constantly going on.

So much for lasers. They are in common use now in all sorts of electronic things, used for measurement, in DVD and CD players/recorders, eye surgery, and loads of other common uses plus military uses.