The Scary Red Laser Spotlight
Sometime back in the late 60s on my first job after getting my AA Degree at Pasadena City College (California) I was working with Tetra Tech. It was a small engineering company with geologists and other engineers. A small company in Pasadena California, it digitized maps for oil companies.
I was the digitizer and operated a special drafting board instrumented with sensors. The sensors allowed me to trace squiggles on a large long map, sometimes 10 feet or longer. The digitized data from the maps was recorded on large reels of tape. It was used to locate potential underground oil deposits.
The company was probably also doing some secret government work. No one ever told me that. But I put two and two together. That, along with my 3 years as a paratrooper, and nuclear missiles being very new at that time led me to that conclusion. What to me cinched the idea of secret government work was I knew of a secret military base, a no fly zone, and had seen the military guard dogs when I was in another part of the country.
It was an interesting, but boring job. What I really liked was being able to use the fast IBM 360/44 scientific computer a couple of hundred feet down the street. It belonged to Optical Research Associates where I ran the computer programs that analyzed the data I had digitized. Data that was used to determine where oil was located underground.
I thought the FORTRAN programs that Pat, their computer programmer wrote, were really cool. They were able to figure out where the underground oil was. It was by using virtually all mathematics to recreate another map that plainly showed the pockets of oil.
A New Technology Laser Experiment
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. They were really being exploited commercially on a large scale. Schools also used them in their labs.
As we discussed properties of lasers and uses for them it was suggested an experiment be done. Those engineers wanted to see if one of their gas lasers could be seen far away. They also 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.” It was 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 away. There was a 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. Something like you see in the movies. However, 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. We didn’t know if we could even to see such a weak 50 milliwatt red laser beam.
Could we See the Laser Beam 7 Miles Away?
I walked into the clearing where the laser was pointed. The laser was some seven miles away. I noticed a weak red light in the distance. As I walked further the red laser light got brighter and brighter.
In the center of the beam, it was the red laser beam shinning directly at us. It was very bright. It was like a big scary red laser spotlight. In fact it was far brighter than all of the lights you could see in Pasadena. The lights from the surrounding little cities were weak compared to the laser beam.
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 red laser beam was. Roughly you could say it was about as bright as a setting sun on the horizon. You could see almost no light from the side of the beam. But directly in center of the beam it was almost blinding.
What was also somewhat surprising was the red laser beam width was only about maybe 15 or so feet across. Once you walked past that, the light dropped off very rapidly. Even 20-25 feet from the center there was essentially no laser light. It was then almost impossible to see the now pinpoint of light emanating from the red laser.
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 red laser laser. I wondered how much brighter a more powerful laser would be. What about one that had lenses to focus the beam into a smaller beam width?
My Interest in Science Peaked and has Stayed High ever Since
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. Even a gamma ray laser or one that could pierce metal from a long distance.
So much for lasers. They are in common use now in all sorts of electronic things. Lasers are used for measurement, in DVD and CD players/recorders, and eye surgery. They are used in the military. Now the US Navy has a powerful laser to destroy incoming missiles. Plus we’ve probably all seen or even used laser pointers used in classrooms and and other places. I have two such laser pointers on my desk right now.
Here are the specs of the most powerful one: Max Output 5 MW, Wavelength 532 Nano Meters +- 10 Class III Laser Product. The other, Peak Power 3 MW Wavelength 670 NM Class IIIa.
Copyright © 2010-2021 Charles Harmon