445 diodes and PBS help

[CDBEAM]

Ya...I somewhat agree John.....Blue is cheap....But there is this little devil....sitting on my shoulder that is softly chanting in my ear...." You are being a cheap screw...we want more blue " !!! See pic below of Asymptotic Curve concerning this hobby !!!

Asyemtotic 1.png

[CDBEAM]

I just could not tollerate the reflectance loss @ 85%. I was compelled to order a narrow band PBS designed for 448nm from JML Optical. Part number CPO21361 10mm sq. The people at JML were extremely friendly and responded to a question I had within a few hours !!! Wow !!! NO...I did not tell them I was a Senior Buyer at Thor Labs...anyway...once I get the PBS...I will post my findings !!

See JML at: www.jmloptical.com

CDBEAM

[CDBEAM]

As noted in the previous post...the results of the JML PBS narrow band coated for 448nm:

Transmittance 98.1 %

Reflectance 95.5 %

See attached pics. Test was done at 1152mw with a single 445LD with an O-Like lens.

Just another step into the eventual completion of the Zod Quad. So...NOW I am happy and can proceede !!!

THIS is the PBS I would recommend !! I KNOW Blue is cheap...but I just could not stand to see those 445nm photons

go to waste !!! It was a.......Moral Imperative to achieve the best efficiency possible.....So....to that end....

I WILL be using TE to cool the CU base plate...more on that when I post a ZQuad update....

Triple YIKES

CDBEAM and Terrawatt

[catalanjo]

O-like ....perfection ..?

405G-2 maybe ..


Cheers

[CDBEAM]

Cat,

See attached chart by Solarfire( THANKS SF)...I guess it depends of which metric rules ???? O-like is the best for cost for sure. Look like 405-G-2 produces a greater rectangular beam geometry at 11M than does O-Like ( More square)....BUT 405-G-2 pumps thru more photons !!!

Cost vs. Best Beam Geometry vs. Max.Photons out the ft. end ?????????????

I WANT it all !!!! But in this case....beam geometry trumps power output....If a trade off is DEMANDED....then my personal choice would select optimal beam geometry.....THAT I can see the difference.....the downside of 4 x 92 mW for a quad set-up...368 mW less out the front.....I cannot see...

Anyone else compare O-Like to 405-G-2 ?????

Thanx...CDBEAM and Terrawatt

[Solarfire]

Cat,

See attached chart by Solarfire( THANKS SF)...I guess it depends of which metric rules ???? O-like is the best for cost for sure. Look like 405-G-2 produces a greater rectangular beam geometry at 11M than does O-Like ( More square)....BUT 405-G-2 pumps thru more photons !!!

Cost vs. Best Beam Geometry vs. Max.Photons out the ft end ?????????????

I WANT it all !!!! But in this case....beam geometry trumps power output....If a trade off is DEMANDED....then my personal choice would select optimal beam geometry.....THAT I can see the difference.....the downside of 4 x 100mW for a quad set-up...400mW less out the front.....I cannot see...

Anyone else compare O-Like to 405-G-2 ?????

Thanx...CDBEAM and Terrawatt

One major test is missing here and that is the cylinder corrected 405-G2 setup which is actually the way to go with the 405-G2 lens. Tests show that the best combinations are the O-Like with prism correction and the 405-G2 with cylinder correction. Both will give a divergence < 0.7mrad and equal far field beam geometry, but the beam @ the aperture of the 405-G2 cylinder corrected will be approximately 3.5mm and the O-Like will be 4.5-5.0mm.

In general I guess one could say a short FL coli is best cylinder corrected and longer FL coli is best prism corrected.
I personally prefer the 3.5mm aperture output.
Cheers!

[CDBEAM]

Thanx SF for the update !! I have a set of Dr.Lava cylinderical's to experiment with. What is the comparison concerning Total Power loss for:

A) O-like + prisms
B) 405-G-2 + Cylinderical lenses

I have experimented with the Lava lenses....and the prisms are MUCH easier to set up....that I know !!

When I am knife edging.....3.5mm vs 4.5mm really is a non-issue as the knife edge is parallel with the .7 or .8mm
geometry....so I guess I would chose the .7mm of the O-Like vs. the .8 of the 405-G-2 !!

The final point of decision then becomes the Total power loss of one set up vs. the other ??? Ouch....ALL this optic stuff gives me a head ache !!! Pass me a Grolsch !!

CDBEAM

[Solarfire]

Thanx SF for the update !! I have a set of Dr.Lava cylinderical's to experiment with. What is the comparison concerning Total Power loss for:

A) O-like + prisms
B) 405-G-2 + Cylinderical lenses

I have experimented with the Lava lenses....and the prisms are MUCH easier to set up....that I know !!

When I am knife edging.....3.5mm vs 4.5mm really is a non-issue as the knife edge is parallel with the .7 or .8mm
geometry....so I guess I would chose the .7mm of the O-Like vs. the .8 of the 405-G-2 !!

The final point of decision then becomes the Total power loss of one set up vs. the other ??? Ouch....ALL this optic stuff gives me a head ache !!! Pass me a Grolsch !!

CDBEAM

The loss of the 405-G2/cylinder setup is with 15.3% overall slightly less than the O-Like/prism setup with 16.8% overall loss. The main advantage lies in the smaller beam size @ the aperture of 3.5mm vs. 4.5mm which will give less loss on the scanner mirror aperture @ higher scan angles.

To the question of knife-edging 4.5mm vs.3.5mm is a question of what losses you can live with when it comes to the scanner aperture. A quad 445nm with O-Like and prisms set with Zoofs prism template to Brewster’s angle will give a magnification of about 2- max 2.5 giving a beam @ the aperture of about 4.5mm x (2.2 x (4 x 0.8mm)) = 7mm. If a quad with drlavas cylinders is possible, I don’t know, that depends on the clear aperture of the cylinder lens.

A major factor in deciding which to use, is the alignment issue; yes the cylinders are much harder to align. In my case well worth it though, because I need the smaller beam @ the aperture, which allows smaller scanner mirrors and therefore higher scan speeds. Either way you go, you’ll have the best results possible (without spending an arm and a leg for optics) with either the prism or cylinder version in the above named combinations. If you can live with the bigger beam of the O-Like then that’s absolutely the way to go.

Cheers

[CDBEAM]

SF...Thanx for your efforts/time on gathering your data !! I will experiment for my optical quad set-up. Like I said...Beam quality...which is driven by how close the beams can be stacked...will win out over power...for me.
Even though it gives me pain to lose 1.5% PO...a more compact stackage delivers increased percevied brightness ( I think ) and a better looking beam profile. I will likely be using my quad with the DT-40 Wide scanners...which also tip the scales toward the O-like + Prism set up.

Thanx...CDBEAM

[flecom]

I didn't have an issue combining 445's with a broadband PBS from the group buy a while back... one | and one - got 2.4W out

the LW cubes don't pass 445 very well at all but reflect it ok