Diode Lasers - Under the hood 02

There is so much to be learnt from the way that a CO2 laser beam behaves. The long wavelength beam interacts with clear acrylic in such a manner that it reveals all of its secrets. The biggest secret being that it is not POWER but INTENISTY that is responsible for damageing materials. There is no way to see this effect with fiber or diode lasers because there are no equally suitable materials available that respond to the short wavelength light. The open nature of a CO2 beam system allows investigation of the beam INTENSITY profile both before and afetr it passes through a lens. The results are suprising.

[@emptyhollow6707]

I enjoy your lectures very much and this one is no different. Thank you for great presentation.

[@SarbarMultimedia]

Thanks for the kind words. Lectures sounds as though I am an expert. Remenber I said I have never touched a diode laser so at this moment I am definitely a student of the subject. However, I am sharing information and experience that I have gained on other laser types and am using this data to predict what I will find when I start tesing the diode beam. I am not aware that anyone else has tried to decode how diode laser work (at the damaging material level) so I have no other reference works to refer to. This will be new to us all.

[@ShopperPlug]

Excellent explanation. Always wanted to learn more about the optics on lasers, specially on diode lasers. Seems like no one on youtube talks about them in detail. How can it be possible to take a diode laser and make it's spot size extremely small using various types of lens? What does anamorphic lens do? Thanks.

[@SarbarMultimedia]

Hi
I understand your frustaration about RUclips videos. Everyone want's to share what they can do with their laser but nobody is taking the time to understand even the basics of what makes the technology tick. Having spent many years experimenting to self-educate myself on various types and wavelength lasers, I am a latecomer to 455nm lasers because they are low power, slow and have a very limited range of materials they can damage. They seemed very uninviting and I thought it would be simple to trasnsfer my other knowledge to this technology. However there are still some surprises that I did not expect as I dig deeper into how these devices actually work. Lense and laser beams are like a marriage made in hell. On the surface they seem to work ok but when you understand what is really happening, things are far from efficient. I am still a student exploring so I will let you catch up with the series to find out what I have discovered so far.
Thanks for the interest

[@octoaquatics]

in the next video you’ll show us how to cut clear acrylic with a blue diode laser!

[@SarbarMultimedia]

Sadly physics will not allow me to do so. Logic says if you can see through glass or any clear material its because the lightwaves are passing right through and almost zero energy is absorbed. Remember your laser is visible blue light and glass or clear acryilic does not absorb it. There are ways to mark clear acrylic by adding a light absorbing coating to the surface. It is that substance that absorbs the light energy, heats up and in turn damages the surface of the clear acrylic. So, sort of engraving yes, but cutting no. Black acrylic is the only colour you can cut successfully because the black pigment ( carbon black.....basically soot /pure carbon) will absorb energy and allow you yo transfer heat to effect a cut. Remember that black is not a colour. it is total absorption of visible light energy so none of your blue diode rays will be reflected, hence the reason it will cut.

[@octoaquatics]

@@SarbarMultimedia yeah i knew it. i figured if anybody could think of a way it’s you!

[@FSEAirboss]

Another educational video!
I do wonder if there is an error on the first chart for what with the NM and Freq. Is CO2 cycles correct? The NM is I believe correct. I would think it would be a lot higher the the previous value. 10,640nm versus 1064nm cycles.

[@SarbarMultimedia]

You had me worried that the gap between my two remaining grey cells was getting worse. I anticipated I may have missed the fact the the answer from the online calculator was in Mhz and I had forgotten to add 6 noughts, I checked the numbers again and both values are correct. The CO2 wavelength is 10x longer so the frequency will be 10x less.
I greatly value comments such as yours because it means you are absorbing all the detail. .So, many thanks.

[@FSEAirboss]

@@SarbarMultimedia Apparently its my brain cells that are fried! :D I had reversed that in my head and I should have validated it before posting. Well, at least its fodder for the algorithm. Sorry for the trouble if any caused.

[@adammontgomery7980]

I just hear Michael Caine