Science Fair Experiment at school

[Shakeandbake]

I am 15 years old ( 10 grade) and just joined the forum. I am interested in doing a science fair project where I can test the intenisty of the laser beam after it travels through different types of lenses. I was thinking of using the IR thermometer I have seen used on this forum as a laser power meter to measure the effect on the beam strength (intensity/thermal output) ) after it passes through various lenses. I am hoping some may increase the strength and others lessen it. At least that is my initial hypothesis. I plan on purchasing some lens assortment from Meredith instruments for $25. I hope they have some of the following:Bi-Concave, Bi-Convex, Plano-Concave, Plano-Convex lesnes in the kit. My thought if I use a laser pointer or somehting inexpensive like that I would be simulaitng how I think a cutting laser works with an external lens concentratiing the beam strength to cut the metal.

Anyway I may be over my head here and am not making much sense. I would appreciate any help, ideas, suggestions or resources on how or where to get materials, etc. to do my experiment.

Thanks

 

[ShortyInCanada]

Hello to you Shake&Bake. :wave:
Welcome to LPF, even if you aren't quite the age. At least you are up front about it, unlike some others...:tsk:
Take some time to look around and read, read, read. Try the search function and learn how to use it. Figuring out the keywords to use is the hardest part.:thinking:
As a tip I will point out if you are thinking of replying or posting to a thread check how old it is first. If the last post was months ago and you don't have a significant question or thought you might want to skip posting that time. It's a common occurrence here to find newbies posting "That's interesting/great/new to me..." in a thread that was done many months ago.

As far as your question goes, you will need to do a web search for the asst. lenses. I have seen a "kit" for what you are describing somewhere a while back for a good price but I think that even that might be out of your range as a high school student. Perhaps contacting local eyewear businesses or eye doctor offices explaining your needs might get you some "old" equipment they have collecting dust.
For the output you need to factor in the area of the beam in your plans too. As your technique for measuring thermal output will be dependent on only the area that the IR thermometre sensor reads from you will need to measure the entire area of the beam and calculate the total thermal output for comparisons. Only then will you be able to determine the loss from the lens.

Now lets see what others might have to add here too....