Diode Lasers---Under the hood 03

We are not quite finished with the theory and trying to decode the internals of a diode head before we start testing. I know what I am looking for in the way of a beam intensity profile to achieve successful cutting and I explain the reasons. I anticipate from all available marketing diagrams, what the baam profile might be and explain how it affects performance.
Ther is also a big difference in the way a lens treats a Gaussian intensity profile laser beam to the almost uniform intensity of a diode beam.
The next video must be fitting and powering up one of the diode heads to begin real world testing.

[@rjlatheart]

thanks Russ

[@bob_mosavo]

Thanks 👍

[@jeanbarbier9448]

Hello Russ,
Something is bothering me since the end of the last video with multi-diode lasers.
I fail to understand how semi-reflecting mirrors (that basically throw away half the power in the "wrong" direction) can sum two 6W-laser beam into one 12W single beam.
Logically half of each should be thrown away...
There may be a trick with polarization, i.e. horizontal polarization being reflected and vertical one going through, but then I fail again to see how that could work with more than one mirror.
Any idea how that magic works ?
Anyway many thanks once again for all your work
Cheers

[@SarbarMultimedia]

Hi Jeani
It's not quite as complex as the direction your imagination takes you. First take a piecs of flat glass and remember this is normal visible light (albeit just one colour) and if you shine a torch through the glass you do not lose 50% of the light. I am not an optical engineer (as I often tell you) but I know that when I use a beam combiner on a CO2 laser the MEASURED loss of power transmitted is less tha 5%.
A quick look at this beam combiner spec may put your mind at rest. I am sure there are small losses but not huge.
www.edmundoptics.co.uk/p/427nm-125mm-diameter-dichroic-laser-beam-combiner/28842?gad_source=1&gclid=CjwKCAjwkuqvBhAQEiwA65XxQDno0pZcbuuGkiZxeH-zLMPnUt5NoH4MuheIcVk_YcxxoTs7Mp0vghoCiEYQAvD_BwE

[@jeanbarbier9448]

@@SarbarMultimedia OK Russ, I had not considered the possibility of every diode-laser having a significantly different center wavelegth.
Obviously, in that case it is possible to have dichroic mirrors reflecting only a very small part of the spectrum (the specific laser small distribution) and transmiting with very low loss the rest.
Thanks for enlightening me.

[@chrisw1462]

A little obsessive about what things _aren't_ (like depth of field), and rather distracting from the stuff that does matter.