Hypothetical white light diode

[absolom7691]

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!

[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

[absolom7691]

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

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!

[mixedgas]

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

Steve

[VDX]

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

[buffo]

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

Gas lasers for life, lol!

Adam

[absolom7691]

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.
🤔

I love Les's videos! Great stuff!!

[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.

[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...

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.

[absolom7691]

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...

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...