Hypothetical white light diode

Curious if there are any single-can multi-chip (rgb) diodes out there. Not sure about the feasibility of this but couldn't three chips be stacked to use the same broadband resonator optics and therefor produce "white" light with the red, blue, and green all having the same divergence and perfect alignment, similar to stacking an argon and krypton tube and lasing through both bores? I'm interested to know how difficult it would be to align three diode chips when we're talking sub 5µm emitter sizes (not for me but for LD producers). OSRAM? Oclaro? Nichia? You guys listening?? lol

Can you tell how much I hate aligning my projector and miss the simplicity of a mixed-gas or AR/KR setup with a perfect white-light beam? Also, imagine how simple and how small an optical deck would be in a projector!

problem is the die-air interface IS the output coupler, and some of these have stacked strained quantum well layers for tuning/HR mirror etc. Might be possible but would require a MAJOR research effort to do so, probably easier to put combining optics into the housing at a micro scale.

You need some one far more skilled then me to comment.

Also modern dies push the energy density limit, so...

Steve

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Originally Posted by mixedgas

problem is the die-air interface IS the output coupler, and some of these have stacked strained quantum well layers for tuning/HR mirror etc. Might be possible but would require a MAJOR research effort to do so, probably easier to put combining optics into the housing at a micro scale.

You need some one far more skilled then me to comment.

Also modern dies push the energy density limit, so...

Steve

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Thanks, Steve! I can always count on you to pop my balloon with sound science! lol. I figured it was probably not feasible or not practical, otherwise LD manufacturers would probably be doing it. I would imagine such a diode would be great for miniaturizing light engines for all kinds of products.

Oh well, back to my kinematics!

Such a diode does exist, it's a hot cathode gas filled device known as ion laser.

Steve

... search for "quantum-dot-lasers" :cool:

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Originally Posted by mixedgas

Such a diode does exist, it's a hot cathode gas filled device known as ion laser.
Steve

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:D:D:D:D:D:D:D

Gas lasers for life, lol!

Adam

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Originally Posted by TheHermit

https://www.youtube.com/watch?v=w1wSHizmbYg
Great!
Fiber fed, remote, truss mounted, scanning heads, from a solenoid pickoff distribution manifold and the fragile ion gas laser(s) remaining safely inside the road case, located backstage on the deck. instead of being manhandled on top of 10' scaff towers, like I tried developing in 1982 (couldn't afford RYGB AOM * 4 distribution & colormod).
But, that was long before today's inexpensive, truss mounted diode laser projectors existed.
Of course, with this continuum fiber optic laser, colormod is still a problem, especially w/o specific narrow output frequencies.
🤔

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I love Les's videos! Great stuff!!

Constant tweaks of alignment aside, the thing that really sparked this was Pangolin's Beam Bush. It's such an awesome looking tool until you see the different beam profiles exaggerated by the Beam Brush optics. Now, I'm sure in some instances, that effect is cool but I would rather see one homogenous beam used with it. It looks like the only way to get that would be to use a multi-line mixed-gas laser. Even OPSL would need perfectly match beams with absolute perfect NF/FF alignment.

Design/adjust the individual diode collimators to have the same divergence. Mix the the beams, run the mix through an apochromatic spatial filter with a input aperture to limit the incoming superimposed beam diameters to the smallest present and then through the spatial filter aperture to clean up the beam. Then another apochromatic lens to recollimate. Should be fairly good. Or am I missing something? You'd be throwing away power, and accepting the worst case divergence, but...

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Originally Posted by absolom7691

Constant tweaks of alignment aside, the thing that really sparked this was Pangolin's Beam Bush. It's such an awesome looking tool until you see the different beam profiles exaggerated by the Beam Brush optics. Now, I'm sure in some instances, that effect is cool but I would rather see one homogenous beam used with it. It looks like the only way to get that would be to use a multi-line mixed-gas laser. Even OPSL would need perfectly match beams with absolute perfect NF/FF alignment.

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Originally Posted by laserist

Design/adjust the individual diode collimators to have the same divergence. Mix the the beams, run the mix through an apochromatic spatial filter with a input aperture to limit the incoming superimposed beam diameters to the smallest present and then through the spatial filter aperture to clean up the beam. Then another apochromatic lens to recollimate. Should be fairly good. Or am I missing something? You'd be throwing away power, and accepting the worst case divergence, but...

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While I love the idea of adding a spatial filter and corrective optics, adding more elements to the optical train would add complexity to alignment for sure. But, to homogenize the beams, this would be a great way to do. I was just hoping for something better to exist.

Don't get me wrong, guys, my first "serious" laser was an ALC60x argon but for the space and power requirements, you can't beat diodes but damn, those beam profiles...

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Originally Posted by absolom7691

While I love the idea of adding a spatial filter and corrective optics, adding more elements to the optical train would add complexity to alignment for sure. But, to homogenize the beams, this would be a great way to do. I was just hoping for something better to exist.

Don't get me wrong, guys, my first "serious" laser was an ALC60x argon but for the space and power requirements, you can't beat diodes but damn, those beam profiles...

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I agree on all points, without disputing Brian's suggestions for creating an optimal beam profile, if starting a projector build from scratch. But, all of those components probably won't fit inside most production projectors.
Yeah, who doesn't love TEM00 beams from ion lasers? I love just watching the tube glow. But, my home doesn't have 3 phase and my well can't sustain 30 GPM. TBH, I still remember the wonderful relief of subconscious tension when that damn pump noise ceased after a long session.
I wouldn't be back into this game, if not for modern inexpensive, aircooled, 110V, RGB diode lasers. But, I digress.

I had a dichroic drift problem with my initial el cheapo projectors. If you have been making lots of dichroic mount adjustments, perhaps the mounts have developed material fatigue, w/o maintaining sufficient pressure against the alignment screws and could be replaced with newer/better ones. Worked for me.
While searching for single mode RGB diodes, I discovered these Sparrow enclosed RGB diode/TEC modules with low divergence collimating optics by Live LaserSystems, Austria. Best gear I've seen so far. (But, I haven't seen Kvant's, TBH.)
Also checkout the doc on their Colordrive One, w/TEC drivers. Phillip, their CEO, online customer service rep, and product technical guru is very helpful and personally tunes everything himself. For example, I mentioned that the far field within my living room is only 25', so he set up the collimating lenses to produce an optimal RGB spot at that range. He fine tuned the TEC drivers too be optimal to the specific diodes ideal temperature ranges.
Like a rich kid in a toy store, couldn't resist scooping up this set of projector bits (6 months, 0% Paypal credit 🙄 ). Haven't built the projector yet to testify on beam quality. But, my expectations are pretty high.
Attachment 61829
Really like that the Sparrows' optics are well covered from contamination. Also, there's only one ribbon bus cable that connects all of the drivers together, reducing air blocking cable clutter.
Their dichroic mounts look pretty solid, as well.
Hope this helps to solve your beam drift and profile woes.

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Originally Posted by TheHermit

I agree on all points, without disputing Brian's suggestions for creating an optimal beam profile, if starting a projector build from scratch. But, all of those components probably won't fit inside most production projectors.
Yeah, who doesn't love TEM00 beams from ion lasers? I love just watching the tube glow. But, my home doesn't have 3 phase and my well can't sustain 30 GPM. TBH, I still remember the wonderful relief of subconscious tension when that damn pump noise ceased after a long session.
I wouldn't be back into this game, if not for modern inexpensive, aircooled, 110V, RGB diode lasers. But, I digress.

I had a dichroic drift problem with my initial el cheapo projectors. If you have been making lots of dichroic mount adjustments, perhaps the mounts have developed material fatigue, w/o maintaining sufficient pressure against the alignment screws and could be replaced with newer/better ones. Worked for me.
While searching for single mode RGB diodes, I discovered these Sparrow enclosed RGB diode/TEC modules with low divergence collimating optics by Live LaserSystems, Austria. Best gear I've seen so far. (But, I haven't seen Kvant's, TBH.)
Also checkout the doc on their Colordrive One, w/TEC drivers. Phillip, their CEO, online customer service rep, and product technical guru is very helpful and personally tunes everything himself. For example, I mentioned that the far field within my living room is only 25', so he set up the collimating lenses to produce an optimal RGB spot at that range. He fine tuned the TEC drivers too be optimal to the specific diodes ideal temperature ranges.
Like a rich kid in a toy store, couldn't resist scooping up this set of projector bits (6 months, 0% Paypal credit 🙄 ). Haven't built the projector yet to testify on beam quality. But, my expectations are pretty high.
Attachment 61829
Really like that the Sparrows' optics are well covered from contamination. Also, there's only one ribbon bus cable that connects all of the drivers together, reducing air blocking cable clutter.
Their dichroic mounts look pretty solid, as well.
Hope this helps to solve your beam drift and profile woes.

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Ever since you posted that Sparrow URL, I have been looking at their stuff. I have been considering buying modules from them. I'm sure my alignment drift is not just the kinematics. The diode mounts are probably not great and I have no idea what alloy the aluminum base plate is. I'm sure there are a lot of areas for drift. The compact size of the sparrow modules, not to mention how affordable they are, is a very compelling argument for me. I just might break down and redo my projectors. These modules would allow for a smaller baseplate which would probably help with alignment drift as the temperature fluctuates.

I could be mistaken but it looks like Kvant may actually be using single-mode fiber to shape the beams on their newest offerings, getting near TEM00 beam profiles. The problem is, Kvant is very pricey, even though their products are great quality.

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Originally Posted by absolom7691

I have been looking at their stuff. I have been considering buying modules from them.

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Cool. In case you haven't noticed, bottom center of all their product pictures that are inside a box, is a hidden mouseover link to more details. You're probably getting a chat panel popping out for assistance. That's probably Phillip, CEO & very approachable tech support. Don't avoid asking him for more info.
One word of caution, an idiot agent of Fedex Customs asked, "Does it emit radiation?" <rut-roh!>, then impounded my parts.
Then she would ignore our explanations, until I complained and went over her head. She would reply that some generically described form (instead of FDA-2877) needed to be completed, without providing a link to the required doc. Eventually, we were able to convince her that the lasers are OEM components, that live inside an enclosed projector case, and are not not for retail resale.
This nonsense went on for a month, until the 2nd Customs agent released my parcel.
A month later, I received a bill in the mail for $200 in additional new Customs service fees (not tariffs).

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I'm sure my alignment drift is not just the kinematics. The diode mounts are probably not great and I have no idea what alloy the aluminum base plate is. I'm sure there are a lot of areas for drift.

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I ordered better dichroic mounts to replace my el cheapo drifty ones. But they're still sitting on the shelf, until I repurpose those projectors' components into a lumia projector.
IMHO, it would be very unlikely that the solid block diode mounts are drifting, but more likely that the dichroic mounts are drifting. Most of the inexpensive ones have an alignment set screw pushing against the tensile resistance of the same piece of metal. If pushed too far, the metal is permanently bent beyond of being able to push back against the set screw firmly. Proper design is key. That's why I also ordered Live LaserSystems' dichroic mounts, mostly out of blind faith, after seeing the quality of their other products.

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The compact size of the sparrow modules, not to mention how affordable they are, is a very compelling argument for me. I just might break down and redo my projectors. These modules would allow for a smaller baseplate which would probably help with alignment drift as the temperature fluctuates.

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I love everything about the Sparrows' well thought out design, the collimator lens mounts, the TECs, their easy access should maintenance be required, ...
Their site also provides a long list of assorted mfr's diodes throughout the spectrum. I special ordered the deeper red 642nm diodes and Phillip optimized their ColorDrives for those specific diodes and set up Sparrows' collimation lens to balance NF to fit onto the galvos' mirrors vs my FF projection range of 25 ft. No muss, no fuss attempting to improve beam quality, out of the box.
But, the diodes are only 1/2 of the picture. The ColorDrive One w/TEC is at a different level than other common drivers. For example, the efficiency of the diodes is actively maintained via the TEC, which is controlled based upon current flow. Higher currents (photon power) can be applied, as long as the temperature is well controlled via ColorDrive One + TEC. This also protects the diodes from thermal damage and extends their life.

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I could be mistaken but it looks like Kvant may actually be using single-mode fiber to shape the beams on their newest offerings, getting near TEM00 beam profiles. The problem is, Kvant is very pricey, even though their products are great quality.

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Very interesting, thanks for sharing.
Yes Kvant projectors are very tempting. Just difficult to justify 3* the price of DIY on a restrictive, non profit, enthusiastic artist's budget, if avoidable. I think I'll soon learn whether it is or not.
Different story for working professionals, where return on investment is dependant upon corporate reputations, safe audience scanning, and dependability are legit priorities. Personally, I only need a kill button (remote controlled AC sockets) for protection against static beams burning through the flame resistant screen into my 4k TV. 🙄
I still need to RTFM modern single-mode fiber collimation. Back in the day, I worked with doped quartz fiber that had a cross section parabolic refractive index to keep light focused towards the center, instead of reflecting off the inner surface... an actual 'light guide'.
Also tried miniature lenses ~2-3 mm diameter, with focal lengths dependent upon distance of internal reflections. Sounds similar.
Happy shopping.
Roj