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The Cyan Cannon Vll Build

CDBEAM777

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Just got off Skype with Ultimatekaiser. He had his 577nm running and I got to see 3 watts of lemon yellow laser light with about a 2mm beam. Absolutely awesome! I am green with envy. It has a 40 watt 808nm diode array with tiny separate lenses for each emitter. He says he will eventually do a review of it. Can't say when that will be, but it will be worth seeing......I assure you.
Interesting !!! Would like to see all the optic details on this !

Although the Blue/Green mix is a beautiful color...I have a goal of using the CC build platform to achieve a Lime Green color. Not sure if a Red/Green mix can achieve this ??? Especially in using the Oclarro Red....Matching the divergence geometry will be the challenge !

CDBEAM :thanks:
 



paul1598419

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Yeah, that Oclaro 635nm 700 mW diode has the same divergence as the Mits ML501P73....horrid! It will be a challenge to get that beam shaped to match a green. UK spent a lot of time and money getting all the parts together to build the 577nm he has. Is has a separate heat sink assembly larger than the laser head to manage the enormous amount of heat generated by the 40 watt IR diodes package. The head is bolted down to the heat sink assembly through two 8 amp TECs to a much larger heat sink which is fan cooled. Very loud fan. The driver is adjustable and the whole package is about 7 years old.... so very expensive.

Can't wait to see how you match these beams and how close you are able to get to a lime green color. I am working with diodes that can provide that color at 120 mW alone. It's all very interesting. :thanks:
 

CDBEAM777

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Yeah, that Oclaro 635nm 700 mW diode has the same divergence as the Mits ML501P73....horrid! It will be a challenge to get that beam shaped to match a green. UK spent a lot of time and money getting all the parts together to build the 577nm he has. Is has a separate heat sink assembly larger than the laser head to manage the enormous amount of heat generated by the 40 watt IR diodes package. The head is bolted down to the heat sink assembly through two 8 amp TECs to a much larger heat sink which is fan cooled. Very loud fan. The driver is adjustable and the whole package is about 7 years old.... so very expensive.

Can't wait to see how you match these beams and how close you are able to get to a lime green color. I am working with diodes that can provide that color at 120 mW alone. It's all very interesting. :thanks:
So...." Where's Waldo "...and where is Lime Green ?????

See attached Color Pic...

I would say Lime Green lives somewhere between 540nm and 550nm.
Our eye spectral sensitivity peaks for Day viewing @ 555nm and night viewing @ 507nm...see Wiki ...

https://en.wikipedia.org/wiki/Spectral_sensitivity

So...we get good luminosity at 540nm to 550nm !!

Why Lime Green....because........It is the most obtuse colour / line I can think of !!:wave: :tinfoil::tinfoil::tinfoil:...and...I like the colour !!!

What diode or diodes are you referring to deliver 120mW of Lime Green ???

Now...for divergence...I can get the Oclarro 63193/ Mitsu P73 down to 0.802mRad....and the NDG7475 down to 0.685 mRad....close...but not equal...

I Could always go with two (2) separate sets of C-Lenses !!! Not sure if there is enough room using the CC Build model ???

Well....anyway....I have enough projects stacked up for several years !!!...I will just throw this one on da pile !!:san:

Has anyone combined a corrected Red and a corrected Green LD ?????? :D

Anyway....thanks for Brainstorm'in with me !!!

Later,
CDBEAM
 

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paul1598419

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I guess it depends on your definition of lime green. Looking at your color chart it doesn't appear to be on there. I figured it to be around 510nm, but you say 540nm to 550nm. To me that is a very yellow green. In fact 550 is more of green yellow. IDK. I just want to see the finished product.
 

CDBEAM777

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I guess it depends on your definition of lime green. Looking at your color chart it doesn't appear to be on there. I figured it to be around 510nm, but you say 540nm to 550nm. To me that is a very yellow green. In fact 550 is more of green yellow. IDK. I just want to see the finished product.
Me too !!! That is why I need to mix the colours...to get to Lime Green... You know...that 1960's knish... Avocado colour !! Yikes !!!

Hmmm...CNI has 543nm...Will check that out !!! Likely DPSS....and a lame mW output...and ....a lota $$$$....BUT....with a DPSS ...Divergence will be da Cat's A55 !!! :whistle::whistle::whistle:

Beam Out :san:
 

Alaskan

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Although not lime green, OptLasers makes a multimode RGB laser which uses two 638 nm diodes which are PBS cubed to increase power, then he dichro mirror combines the green and blue with it to make "white". Since combing red and green makes a yellow appearing beam, of course different mixes of power would produce a lime color, but what I wanted to show here is how he used cylinder lenses with the red diode output.



The round glass in front of the right most red laser diode is a wave plate.
 
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jors

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It is possible to get a solid yellow on multimode diodes with a pair of PBSed P73 and one 700mW or 1W 520 green Nichia.
You have to expand green until about 3mm to get 1mrad (better with cyls), and about 5mm for combined red to get 1mrad as well (cyls again). Accurate NF-FF beam measuring is required on both wavelengths (while adjusting cyls) to match divergences as better as possible. You should measure beam sizes at 25m or more FF distance, and adjust cyls for same G/R beam spot sizes.
Once divergence is matched, you can pass combined beams (yellow) thru an achromat Spatial filter with about 50um aperture (or make your diy aperture with razor-blades Planters technique). This way you clip the red on the aperture edges, while passing thru almost 100% of green. Resulting is a 3mm combined yellow beam with matched divergence.
Another simple way is to bounce combined beam with a 3x3x3mm mirror prism, so clipping red again (out of mirror) to match green diameter. Result is about the same, ie 3mm/1mrad yellow but with multimode noise around beam core on this setup.
On both cases you’re going to loose about 30% of red power due clipping, but because of matched divergence/diameter the emerging yellow if way solid if alignment is done right. >1W nice yellow is possible on both setups. The 'advantage' is you can 'tune' resulting aparent wavelength just playing with the G/R power amount into the mix (from 520 to 638nm), the other one is the cost. The drawback is.. you have to achieve stable alignment and accurate divergence matching, but this is doable however.
 
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Alaskan

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Thanks Jors, great method, I like it, why not shave off that extra red to make a quality yellow appearing beam, agreed. I keep collecting parts to build from ideas like this :) I need to buy a mill and learn how to use it.
 

CDBEAM777

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Thanx Jodi and Chris....Hmmmm...On the Multimode unit above...Opt Lasers does not C-Lens the Blue or Green...Interesting !! But...the Green...Likely NDG7475 needs to be corrected also...I assure you !

And....Do we have room for PBS'ed Oclarro Reds ...and a NDG7475 ??? ...in a HH unit ????Maybe...be we are getting on the really large size !!

Thanx for the explanation Jordi !! As usual...you drill down and share hard gained info !!!

Hmmm...When I get to it...I will try a single Oclarro 63193...and a NDG7475...both run thru Opt Lasers cylindricals...and see what color and geometry pops out !!

Based on my Opt Lasers Cylindrical lens tests....the divergence is somewhat close....so...maybe we get lucky !....and the colour is close to lime green !

Surly, the NDG7475 will be driven by the adjustable Black Buck 8A....and...Spatial filtering is inexpensive and takes up little room.

SO...I want it all...DIY for cost savings, manageable footprint with just dual LD mixing, A Lime Green colour, Reasonable PO...and somewhat matched divergence for Far Field equity.

Just another " Mountain to climb "...The " Lime Green Hydro Dream "...LGHD !!! Hahahaha

Beam Out !
 

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paul1598419

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IDK, I think the spatial filter in this case is just overkill. Because of the different wavelengths of 635nm and 520nm passing through the same filter, the only gain you will get is clipping of the 635nm beam. That could be done more easily without using a spatial filter which is used to clean up beams passing through optics. No matter how well made your lenses are, they always introduce some noise into the beam and spatial filtering cleans that up better than anything else out there. We used them in holography to clean up the noise introduced with optics in the system, but using one to try to clean up a combination of wavelengths seems like it will clip the 635nm and do nothing more.
 

jors

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I've been done lots of SF with combined wavelengths on my modules and yes, it clips 638 (if required) but also cleans both wavelengths, granted (you have to get a perfect NF/FF alignment first). You must go with achromatic lenses and find which aperture diameter better suits your needs (usually in between 30-70um).
This is the only way to effectively clean multimode diodes. And yes, as I said there's a simple-cheap way to clip the red while avoiding diffraction patterns (rings etc), and this is just bouncing to a mirror of desired size...such a 3x3x3mm prism mirror for a 3mm 638 size beam output,
..but in this case you're not going to clean the beam, so trash is still surrounding beam core.
plz take a look:
http://atenlaser.com/shop/index.php?id_product=16&controller=product
 
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paul1598419

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I looked at your link, but since the refraction of different wavelengths in the objective of your spatial filter, it seems each will converge at different distances making two miss the pinhole entirely. The spatial filter works by having your beams focus point be exactly at the pinhole. Since the glass has a set refractive index and this changes with wavelength, how can a single lens be used for multiple wavelengths.... especially wavelengths so very far apart?
 

jors

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This is why I go with achromatics doublets/triplets positive lenses on my RGB SF, to minimise focal shift because of refractive index. They work pretty good..of course lenses must be high quality.
 
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paul1598419

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I suppose you can minimize it to an extent with compound lenses, but it will always be there. The very best spatial filters use the smallest pinhole possible making any shift problematic.
 

CDBEAM777

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Sometimes...I feel so very....humble....in my limited knowledge of Optics !!:bowdown::bowdown: Really !!! I still have so much to learn !

Thanx Paul and Jodi for the explanations !

All things considered...I may have room for a simple pinhole mask....but a Spatial Filter....ala Atten Laser model ??? :thinking::thinking::yabbem: again...a much more perfect solution....but....needs lotsa room !!! :whistle:

See pic to visualize my true feelings. :crackup::crackup:

CDBEAM
 

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paul1598419

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You are too funny, CDBEAM. You are not a noob in optics. Not with all you've accomplished here. :crackup:
 




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