Well...Quite a lively conversation !! SO...We must ask ourselves...." Why were these FAC lenses added to any multimode diode " ???? What was/is the final desired engineering outcome ??? What is the application ????? Surly...Hundreds of thousands of $$$ were not invested so that we may enjoy reduced.....or Zero Bar geometry in our HH applications !!! HAHAHA....That MAY be a unintended coincidence….and I am hopeful that it is....
I have NO idea what the final application is for these FAC corrected diodes ???? But....a commercial application involving thousands of diodes would likely be the guess !!!
Now....let us add " Parallax View " to this debate....!!! When we view the Beam Propagation of an uncorrected NUBM044....as it travels out into the night sky ( Never do this !!!.....because ….Sure as SH!T....an airplane will Pop into existence approx. 0.3 seconds just before one turns the beam on !!!! DIRECTLY in front of your Beam ) …...What do you see ???? Basically a beam !!! NOT a Fan/Bar...one see's a BEAM !!!!.....and this is because Human Parallax View comes into play....SO...What is my point ????
" Parallax View " is a great Physiological aspect of Human eyesight !!! ….It does a perfect job of making a less than perfect Gaussian profile beam. ( Where X does NOT equal Y )...look really good/Beamlike.....at Infinity focus !! SO....what we are really after ????
IMNHO...we are after the perception of a fairly equal divergence....SO...X =Y divergence...as close as possible...in the "Medium Field".
Now...you will ask....WTH is the " Medium Field " ???? ....Well....I would say it is the distance between the Nearfield and the LOS ( Line of Sight ) …..SO....From the HH output....to how far our unaided Eye can see....It is this distance I call the " Medium Field ". I speculate that the FAC will deliver..... the perception....that X=Y in the Medium Field… Just my SWAG....We will see shortly !!! Pass the Popcorn !!!
CDBeam
My fear is the square output was designed for home CNC use and not for holding beam shape over distance, I wonder can a single FAC lens placed close to the facet compare with a C-lens pair set after the coli lens ? The physics suggest no but I hope to be amazed.
The line output FAC corrected diode may be better at holding it's beam shape over distance as it's dimensionally reflective of the P/N junction and I don't see the square output FAC corrected diode as having enough physical space to match axis length and correct divergence is such a short distance given the line shape of the P/N junction ect.....but I hope it has done the magic that we desire and I am very curious about the shape of the FAC if it has.
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One step at a time. First is to observe the dimensions of the spot size at various working distances. Then you'll know which diameter collimating lens will do you job.
Yes I agree and that's information we don't have yet and no issue once in hand, no issue what so ever once in hand.
G2 was just an example of a given lens at a given point of focus/infinity for comparison of FAC corrected diodes.
My dilemma as the price plus shipping is now 150.00 range each diode is which version of FAC corrected diodes will be better at maintaining beam shape over distance, lenses can be adjusted, but how well the FAC has adjusted the divergence of the fast axis is my question.....yes I know we will have to wait and see.
I am interested to know how well these FAC corrected nubm08 diodes compare to a 6X c-lens corrected nubm44 which is a sister diode only wavelength is 455 vs. 445 however raw divergence and output is comparable, and I don't expect they could be any better but they would be more convenient for PBS combining and knife edging, the line output FAC corrected for knife edging and likely the square beam output FAC corrected diodes for PBS combining.........but maybe not, not if one holds it's beam shape better over distance than the other, I am not building a CNC for point blank only use and I fear the square beam FAC corrected diode may not hold it's shape over distance as well as the line output unit might.....again I know we will see in time.
I also have NDB7A75 c-lens corrected beams that are very good and do 5w which I seriously doubt a single lens FAC could match, I would be happily surprised if they are as good or dare I dream better, but given the physics I imagine they are not, however if pretty good then let the beam combining begin.
My issue is how many do I buy now not knowing how long the supply may last and which FAC corrected version will be better at holding it's corrected beam shape, adjusting optics once in hand is not an issue..........I don't expect a guaranteed answer, just looking for insight.
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huh weird, shipping was free to the US yesterday, now all shipping is $45. They also just started selling recanned NUBM07s / N465? Recanned NUBM07s with FAC are coming next week
As long as the backfill gas has been replaced then GREAT, but if the blues don't have the backfill gas replaced under the new window can I expect they will fail very early as I have seen de-canned blues do again and again, but I have been told that they did replace the backfill gas...........I may go slow to be sure.
