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The Chartreuse Coruscation

CDBEAM777

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Chartreuse Coruscation

Well....yet another new Combiner-Hand Held project..this one is for my collection.....in which I desire to generate a combined 3.0 W output. I will be using the bounce mirror / Dichroic Mirror set up as was used on the Cyan Cannon Build. I plan on beam correcting via a 6X Cylindrical lens set. As before, I must determine if the optics correction can share a common set of 6X….or if two (2) sets of Cylindrical Optics will be demanded.

I propose to use the N520 Green LD combined with the VSHIO HL63283HD Red LD.

The combining of a Green and Red LD...is old news. Been done by Jayrob back in 2014...See http://laserpointerforums.com/f40/yellow-tri-mag-90107.html . BUT...this unit will employ the High PO - Multimode Green and the new 63283HD Red LD...and add corrective optics SO…we will have three (3) new attributes contained within this build…

1) High power adjustable colour mixing from Red ===> Green
2) Corrective Cylindrical optics for Beam shaping
3) The New 63283HD Red LD

Note: As of this time, although I would like to add a Linos 10X Beam expander….I am thinking this may not be possible. The combined Red/Green beam path axis is NOT in alignment with the unit main centre axis. As of this writing, I have not come up with a work-around !

The colour line I want to hit is likely 550 to 560 nm....and it is called "Chartreuse Green" ! How fortunate that our Peak Daylight sensitivity for cones and Rods lies at 555nm. See the attached Wiki link outlining this colour !

For now, this build will be based upon the " Cyan Cannon" HH build platform. Lessons learned / design improvements gained from the Cyan Cannon build be integrated. This build will incorporate the new VSHIO HL63283HD Red LD. Beam correction will be a necessary...as will be matching the divergence of these two (2) LD's.

I will start with a Optical Test Bed set up to establish just what can be accomplished and the resultant colour output of the two (2) mixed beams. Once we establish that the desired colour output can be achieved....then I will go on to achieving parity for Far field divergence matching and minimal divergence for both beams.

The current plan is to incorporate a dual set of Opt C-lenses; One set for the Red LD and one set for the Green LD. I project that this double set of Cylindrical lenses may be demanded to ensure the ability of matching the divergence of these two diodes. Not sure…maybe we can do it with a shared single set of Cylindrical optics.

After this level is attained, then......I will finalize the actual Hand Held design details...and start the build.

As guide for any design…. Two (2) basic things are desirable;
1) Ability to adjust all optics
2) Ease of optical alignment

Unfortunately…. directly linked to the ability to adjust…comes the ability to become misaligned !! If something is mechanically inserted into some channel geometry…with no ability to be adjusted…well…it does not have the potential for future misalignment….but then….how does one achieve the optimal alignment in the first place ???

So, there lies the basic compromise….It can be and has been done. MANY lesson’s were learned with the Cyan Cannon build….and will surly be applied to the Chartuse Corusication build.

The control plan for this set-up will be to run the Red LD at full PO capacity and current vary the Green LD to modulate the Green input only. By mixing the two lines of Green 520nm and Red 635nm we should be able to generate a combined beam of Green-Yellow display...Chartreuse Green.
SO...Can we do it ??....Sure...we can !!

I do not know of another purposeful attempt to use a corrected LD combination approach to achieve this perceived particular color...in the Hand Held format.

For now...the plan is to use a 2D cell Modified Maglite host …as was used in the Cyan Cannon build. Two (2) 26650 or two (2) 32250 LiPo cells will drive two separate drivers. LiPo Cell output will be approx. 8.4 VDC, One of the drivers will be the Worsee 8A Black Buck and this is the driver that will Modulate the Green ND 520 Diode.

Not sure on the shroud/canopy arrangement....likely the standard full Acrylic canopy ????

This is a large build....but then...the optics design demands this. It will also not be a light weight unit....so...it can always be used as a Nutcracker in a pinch !! Hahaha

Stay tuned in the coming months to see how this unfolds !!

I just cannot and will not wait...until a High Power / 555nm LD pops up on the market !! Forget That !!! Will the beams be a totally PERFECT MATCH ???? NO...So what !!! We will get CLOSE !!

See this link: https://en.wikipedia.org/wiki/Chartreuse_(color)

CDBEAM
 

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Alaskan

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Nice project, looking forward to seeing how it works out, but if I were doing it my preference would be to have some kind of adjustment to make it more yellow or green and build two of them so I can have one too :)
 

CDBEAM777

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Ah...It will have adjustability on the colour range. Hard earned lessons on the Cyan Cannon build will be applied. Red LD at full output...Green LD adjustable.

Also...New Lasertrack mounts...for Planar optics....with a new design for setting the X-Y location...from the OD of the H-BE.....

Always looking to build something ...well...As simple as possible...with as much ease of access to the mount adjustment points.

Again...Hard earned lessons from the CC Build !!!

Build Two (2) you say....well....yes......I would.


Hey Paul...You asked for it !!

CDBEAM
 

CDBEAM777

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Thanx.....Let's put these on the Fast track....say....B4 the snow flies in Dec 2018.
We are building now...using many, many lessons learned...from prior multiple builds.....things Should move much quicker....Should.... !!!!

CDBEAM:beer::beer:
 

paul1598419

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Another interesting project, Bob. Besides the problem of the beams not being on center with the axis of the host, you also have the problem of chromatic aberration with use of a BE. I am looking forward to seeing how this turns out for you.
 

CDBEAM777

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Another interesting project, Bob. Besides the problem of the beams not being on center with the axis of the host, you also have the problem of chromatic aberration with use of a BE. I am looking forward to seeing how this turns out for you.
I may have a way to centralize the combined beam-on-beam path to provide aligned geometry for the BE. The combined beam path is currently 8.5mm off the unit central axis.

As to the issue of chromatic aberration .....well...this Law of Optics seemed to not be in play with the Cyan Cannon....but then...different colour lines/ diodes....may change this completely !!

To me....the BE is desirable....but....most of the " Heavy Lifting " for divergence correction is done by the Cylindrical Lens optics.

In this case.....I will work on a centering geometry work around.....and since I already have the Linos unit.....well...I will give it a try.....while the LD's are in the Optical test bed.

No extra cost to take a quick look. I will design the H-BE as though the Linos can be used. If not....then...Oh well !!

Thanx for the heads up !! We have talked about the problem of chromatic aberration before !! It may be a real problem with Red/Green mixing....whereas...not a problem with Blue/Green mixing ???? Dunno ??

I will find out.....in the coming months.:undecided:

Added....Our discussions are coming back to me Now.....in that Chromatic Aberrations give rise to unequal Focal Point distance as a function of NM....and this limits Spatial Filtering to eliminate/reduce off-axis junction propagation....Wow....that's a mouth full....I may even know what all that means !! :drool::drool::drool::crackup::crackup::crackup:

Ahhhh...All that Gobbledie Gook may be true....but...ya know...I will still give it a Whirl !!!!! :thinking::thinking::thinking:

CDBEAM
 
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paul1598419

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I would expect the greatest chromatic aberrations to be with wavelengths that are farther apart. Like combining red and blue. It remains to be seen if you have a problem with it here.
 

Alaskan

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We need an achromatic beam expander lens set (E: for the cylinder pair too, but perhaps that's a unicorn).
 
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paul1598419

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I guess the only way to find out is by experimentation. The closer together the two wavelengths are, the less of a problem this might be. I really have no idea what aberrations might be had running two different wavelengths through the same cyl pair. I suspect the more optics that are involved, the more this could become a problem.
 

CDBEAM777

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Well...As it was done with the Cyan Cannon....A test bed arrangement was first constructed to verify the outcome of the colour mixing and determine if one (1) set of Cylindrical lenses would suffice...or that two (2) sets were demanded.

SO.....I will add to that procedure and position and test the combined beam output with the Beam Expander employed...and see if Chromatic Aberration comes into play.

I would suspect that there will be some degree of Chromatic Aberration....but....hopefully it will be limited and within tolerance.

Fortunately, our application is more general and not Military, Medical or Industrial.....SOOooooo, we got more " Wiggle Room " !

This " Wiggle Room" does not translate into lowering our goal of perfection.
That Target remains.

We shall see !! Thanx for the support !!

Beam Out
 

Alaskan

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I've been eyeing some nice achromatic lenses for awhile now just for this purpose, but the cylinder pair, ouch.... never heard of an achromatic cylinder pair, the collimator half of it surely will have the same problem as any other single element lens would, the expander or concave lens of the pair too for that matter due to the different wavelengths bending at different rates to one another through the glass, if the wavelengths of the two diodes are spread that far apart. Red and green is quite a stretch, but so was green and blue in the Cyan Cannon. However, for $$$ you can buy brand new achromatic beam expanders, they are available, just haven't seen that for our 2, 3, and 6X cylinder pairs yet.

https://www.thorlabs.com/newgrouppage9.cfm?objectgroup_id=1580

From the above link:





Edit: Our Italian friend Minamoto Kobayashi/Richardo turned me on to these, I just remembered, I believe you built a pointer for him using one of them, so maybe I'm preaching to the choir! (that exclamation mark CDBEAM inspired) Only problem with these Thorlabs achromatic beam expanders is if you go over 5X, the input aperture is too small for the output diameter of our higher power multimode laser diodes, as most members have seen from me in the past, 1 inch expansion is too small for my likes :) - The Cyan Cannon was a compromise to save money, since I had that 3X expander at such a great price from eBay, only 75 dollars, but it also had a extremely high power density YAG (with LBO crystal for VIS) AR coating which I liked, so went with that. I don't think those 8x Linos beam expanders you find on eBay can take it and now that I'm on this subject, I'm starting to remember Roberto had damage to his Thorlabs Achromatic (above). Robert, am I remembering correctly, or which BE was that he burned the input lens on with his uber high power NUBM44?

 
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RedCowboy

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If it can be done for a cameras telephoto lens it can be done for a multi wavelength beam expander, it will likley use additional lenses, some of the camera lenses I have torn down have a dozen lenses, but for 2 wavelengths it likely won't need as many, but still some additional.

 
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CDBEAM777

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Well....I seem to remember that Richard fried a Linos BE on a 044 LD...IIRC ?? It was NOT AR coated for the 450nm line....and was in harms way positioned at the Near Field....so..."Poofff"...went the AR coating !!! At over 5W of output from the 044....and the beam before it entered the BE was corrected by Cylindricals....well....Over the Top Optical Power concentration resulted....and this concentrated power damaged the AR coating.

The Linos BE I have...IIRC ...is AR coated for optimal at 532nm....and I will be at much lower power levels....SO....Should be OK.

Now...Let's discuss testing of the Cylindrical lenses to determine optimal Lens to Lens separation distance.

See here...https://laserpointerforums.com/f42/cylindrical-lens-advanced-test-bed-clat-b-95252.html

OK....So this "CLAT" unit was set up to determine the optimal distance between PCV ==> PCX Lenses.

The bottom line is...If Two (2) sets of Cylindrical lenses are needed....it can be done....just more " Optical Adjustment Dilly, Dilly" " OADD " is another term that should now be in our Lexicon !!! You can thank me later for introducing yet another silly nomenclature !!!...and two (2) sets add more cost !!!

Now....you may likely ask...Do you have a Beam Profiler....No...I do not...that is on the list to build !!! It is a ........ L o n g ....... L i s t !!
I use digital calipers and My eyeballs !! This method probably gets us 95% to optimal placement !!

So....This is how I will determine if we need one or two sets of Cylindrical lenses. I hope only one set !!!

I am relatively confident that the current Cylindrical Optics are fine.....being 6X from Opt Lasers.

For combined beam centralization...I now have a design solution...and will post that shortly.

We inch forward....and hope for the lest expensive, least complex set up !

CDBEAM
 
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CDBEAM777

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Well....I did another concept drawing, showing a single set of Cylindrical 6X lenses.

I am sure this can be done with the same OD as the Cyan Cannon. You may ask....what is so special about the Cannon Geometry. It is the OD. At 57.15mm OD....I can select an Acrylic tube of 57.15 mm (2.25") ID...Perfect fit. SOooo...this is why I choose to limit the OD to 57.15 mm.

SOoooo....If we can live with a single set of 6X Cylindricals.....Which I now believe we can.....The combined beam output can be centered. A Beam Expander can be added.

See the attached most recent drawing. CHC-H-BE with Optics S6X V3.

IF I cannot sufficiently tame the USHIO HL63283HD Red LD....then....I will settle for the Oclarro 63193 LD.

We crawl forward !!

CDBEAM
 

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