RGB2X_ White Lightning

[Alaskan]

The low .8 mRad divergence of the single mode diodes is attractive, but when I compare the combined output of two of those units at a bit less than 800mw with that of close to 4 watts of power from the multimode RGB laser OptLasers offers for 1100.00 USD, the higher power 1.8 mRad multimode laser produces about the same power density beyond 10,000 meters, a single 4 watt multi mode RGB unit is more expensive but less complexity for us to put together into a host.

I am surprised at this result, I thought two single mode units combined for close to 750mw output would do much better in comparison, but it doesn't:

From this result, I do not see the advantage of combining two single mode units, if using just one unit I see the advantage as far as bang for the buck and a smaller host, but other than that, not so much. From this I'd rather go with the single 4 watt unit expanded to 25mm as it will produce far more power at a great distance (as far as power density) and have a tighter beam than two single mode units combined without expansion.

 

[CDBEAM777]

Alaskan....I see your point !!! OK....If I cannot build two @ Single Mode LD units...I will switch over to exploring using the Multimode LD's.

CDBEAM

 

[Alaskan]

I really thought combining two single mode units would out shine the 4 watt multimode laser, but due to the way the output must be off-set to the side, a large 3 inch/75mm diameter lens for beam expansion cannot be used. However, you had mentioned a beam expander could be put on it, I think there might be room for a 25mm expander, or perhaps a bit smaller? In that case, the dual single mode combined output expanded to 25mm would kick butt over 4 watts of multimode which isn't expanded. Only thing is the symmetry of having the beam squirt out the side instead of shooting out of the host axially does detract from the project for me. Although most LPF members would not see the need for further expansion if the divergence is at .8 mRad, I'm an uber low mRad desiree kind of guy.

If you can build 3 diode SM unit in a host with axial output and at least 25mm expansion, that would still kick butt over the 4 watt multimode RGB which isn't expanded, at least for power density at a great distance, but of course not as impressive looking a beam when leaving the host due to less power. Tossing these aspects around a bit more the dual single mode units would be a good compromise if expanded to at least 12.7mm, even better at ~24mm. If expanded, the dual single mode is still a go for me. I probably ought to have both built, the large MM diode and the dual SM diode units, except with the MM RGB expanded even further, up to 75mm if its output can be made axial, or out the center of the host so a big lens fits right on it.

Don't know if you want to take both on for projects someday, but either are still of interest with additional expansion of the SM unit. You choose

 

[CDBEAM777]

AK, AK, AK !!!!! OOOoooo....Ouch !!!! Me brain hurtz !!See pic !!

OK.....The problem is....the SM...and ....MM Opt modules both have a beam output which is off-center !!!


Other than conventional presentation....there is no reason the Beam Expander cannot be mounted off centre also !!!

We have the room !!! The HBERGB unit is 82.5mm in diameter !! A BE with the typical dia. of about 30mm will fit...but would not be centered on the HBERGB center axis or the host center axis !!

I suppose...the combined output beam could be bounced twice...to steer it back in alignment with the HBERGB and with the host centre axis !! Yikes !!!...Me head is spin'nin again !!!

But...this corrective steering....will demand some added length, lower the optical power out the front door...and....and....make centration of the Beam Expander...just a royal PITA !!

I vote for leaving the BE off-set.... ????

Or......Extend the shroud cover....which I have not yet mentioned....an Aluminum tube....which will slip over the 82.5mm HBERGB unit diameter !!! SOooo...we make this shroud cover longer than the HBERGB unit..extra length equal to the BE length !! Well....in this way....the off-center of the BE would be hidden.....but the beam will still prop off centre....and be off set !!! Life is full of compromise !!! AK, AK, AK

CDBEAM

 

[Alaskan]

OK then, SM with as large a expander aperture possible inline with the optical cylinder so it doesn't become a protruding bump point on the head of the unit. Less fire?

With the single mode outputs combined and expanded to 20mm diameter, this would be 4X expansion and due to the reduced divergence leave the 4 watt MM RGB unit in the dust. With 4X expansion 700mw of SM power would produce more than 6X the power density at 250 meters, 9 times at 500, 10 times at 650, 13.5 times at 5000 and at 20,000 meters, close to 14 times the power density (smaller diameter spot and more power in it) beyond what the 4 watt output MM unit could do without expansion:

Now that's cooking with gas.... For a 3 diode RGB MM combined white laser, without further expansion to reduce its divergence lower than 1.8 mRad, the MM laser would need to produce 56 watts of total output power to produce the same brilliance at distance as these two SM combined units would when expanded to 20mm diameter.

Edit: If the SM laser beam was expanded to 25mm, at 20,000 meters distance the power density would be close to 22 times greater than a beam from a 4 watt 1.8mRad multimode RGB laser could produce. Although, I am ignoring the far field alignment, not sure how well that would fare, but we would have the same problem with either SM or MM combined RGB beams. At 25mm/5X expansion, the MM 1.8 mRad RGB unit would need to produce close to 88 watts of power to compete with our little 700mw single mode laser.

 

[CDBEAM777]

EEEeeee...AH....Me hair is still ablaze !!

OK....I will generate an end view showing where the BE will be....in relation to the Host and HBERGB center axis. See pic !!

CDBEAM

 

[Alaskan]

I though the short guy was more properly me in that drawing, due to my desire to build a laser pointer which could reach out to aliens

 

[CDBEAM777]

I though the short guy was more properly me in that drawing, due to my desire to build a laser pointer which could reach out to aliens

Well no... CDBEAM is just a pupil of Optics....and surly....trying to understand them is very...er..ah....Alien !! :crackup::crackup:

Now...see you the latest iteration WLGA-V7....Updated the detail where the HBERGB is inserted and secured into the SkyRay Host front end/switch cavity.

Also, see in Red...the 30mm OD outline of the Beam Expander XY location...down and to the left !!

I believe this is what is desired ??? :drool::drool:

Note: Please link a drawing of the dimensions for the Beam Expander you propose...Thanx

CDBEAM :beer::beer:

 

[Alaskan]

Don't know yet, needs 5mm clear input aperture or more, 25mm output aperture, or a bit more, 5X. BBAR VIS.

 

[CDBEAM777]

Worked a few mistakes out of the drawing V7...and added some detail. Latest iteration @ WLGA-V8

CDBEAM :evil::evil:

 

[Alaskan]

So far, all I am finding for a off the shelf BE is the Thorlabs GBE05-A but it has a 45mm output diameter: https://www.thorlabs.com/thorproduct.cfm?partnumber=GBE05-A

 

[CDBEAM777]

So far, all I am finding for a off the shelf BE is the Thorlabs GBE05-A but it has a 45mm output diameter: https://www.thorlabs.com/thorproduct.cfm?partnumber=GBE05-A

OK....This Thor Labs BE does have an output dia. of 45mm !!

SO....We need to increase the proposed Aluminum shroud to an ID of 95.25mm. See latest iteration WLGA-V11. With this diameter for the HBERGA...the Thor Lab BE will be within the ID circle of the Ally Shroud. Close by 2mm...but will fit !!

This build is expanding....but....these are the demands !!! :beer::beer:

CDBEAM

 

[RB astro]

OK....This Thor Labs BE does have an output dia. of 45mm !!
...
This build is expanding....but....these are the demands !!! :beer::beer:

CDBEAM

:crackup:

 

[CDBEAM777]

:crackup:

I get it...." Expanding " hahahaha !! .......

" Laugh it up...Fuzzball " !!!!!:eg::eg:

I just know the alignment of Two (2) combined beams...into one (1) Beam Expander....is going to be one big PITA !!!!

Pitch, Yaw, X axis and Y axis...ALL must be perfect !!!

:crackup::crackup::crackup::crackup::banghead::banghead::banghead::banghead:
:thinking::thinking::thinking:
CDBEAM

 

[Alaskan]

Maybe better to use PBS cube instead of knife edge? This thing is expanding

 

[RB astro]

" Laugh it up...Fuzzball " !!!!!:eg::eg:

CDBEAM

All this is way over my head... :crackup: