Increasing the power of a laser beam by the addition of multiple diode lasers of similar but distinct wavelengths. -The correct wavelength for the 3 diodes centers at 636nm.
That is a valid criticism. Our video on laser safety supports your point. My only excuse is these earlier laser videos were produced to present applications to an audience well versed in laser related procedures. The recent and rapid growth of this channel now exposes a much broader audience to all of these videos. I'll pin your comment.
I've spent 15 years working with laser projection systems and have never seen such professional and advanced optical systems, such as the ones on this channel, nor have I ever worn safety glasses. It is very doubtful that beginners would attempting these experiments, with such expensive equipment. Anyone who does already understands the dangers and are very aware of which direction to point mirrors, prisms, and beams. Don't get me wrong, I'm not disputing your concerns, but understand what it's like in the real world of working with visible lasers. But, now that you mentioned it, I must ask, "How can it be safer to work with high powered lasers, if you can't even see them, because of wearing safety goggles?"
Really wish you would use lapel mic because fan noise mask your words. I made spinning mirror laser show circa 73. Your post are the greatest interest to me!
Awesome experiment and results. I remember reading about an industrial cutting laser system that was developed using this technique to achieve incredibly high power densities.
That was a magnificent and detailed explanation, thanks for taking the time and being so thorough. Learned a lot and made me interested in researching further.
Wavelength shift by temperature also happens with LEDs. It's kind of an interesting and surprisingly dramatic phenomenon with them. At 65 Celsius and higher, it's possible to shift a peak 660nm red LED up to 700nm and probably further. The output intensity also goes down dramatically as the temperature rises, which prevents it from being very useful.
You are correct.The reverse effects with cooling are less dramatic, but because of the increase in efficiency with cooling this can be useful. We have intensely cooled the red diodes in the RGB laser projectors I demonstrate in some of our earlier videos.
Very cool video, but notch filtering out the fan noise during post would be a most welcome addition :) I found myself tiring over the duration of the runtime while your previous videos have held my attention rigorously.
Always fascinating video! that technique is interesting! so you are like using identical LD and make them having different wavelenght by playing with temperature gradiant between these and them use a prism pair to recombine the beam into a single one parallel instead of the need of expensive dichroic mirror for really sharp bandpass?
FYI: If like me you’re having trouble following along because of the background noise try enabling the auto-captioning; I was pleasantly surprised to find them quite accurate.
If you were to drive this as if it were a pluggable optic, and channel the light into a fiber, assuming you added that individual temperature control for better convergence and cleaner differentiation, what bandwidth might it be able to push, and would it have any capabilities beyond modern SFPs? How many diodes would you need to add to multiplex dense enough to compare with the 400 and 800 gigabit capable optics currently in use?
Hey Planters, is it possible to shorten a setup like this in size or would it involve bouncing the beam around many times to win the distance? It would be cool (although I'm sure hard) to tec cool a diode seperatly with a tec controller to et the temperature seperation desired to do something like this.
HIDEOUS fan noise would have been easily eliminated by using long tubing to the radiator, maybe even putting the damn thing outside. Also, fans can be run slower to *greatly* reduce _fan noise power, which varies approximately as the CUBE of rpm._ That noisy fan looks like 24 volt DC fans I have, which run beautifully on 12 VDC, and still move a lot of air, but make far less noise.
Do you have any more information on this? I’ve read quite a bit of literature on WDM but I have yet to come across a reference to using temperature to actively control the channel wavelength. I’d like to use a similar technique for an upcoming project.
I don't think it has been done before. Typically, this is accomplished by using open cavity diodes that have a common grating across the entire array to shift the wavelength progressively along the parallel diodes. This also serves to narrow the linewidth of each diode making multiplexing more effecient.
Ti sapphire lasers can be diode pumped, but the peak power or the high beam quality needed for a dye laser make diode pumping difficult. It has been done, as a matter of fact, I built one a few years ago, but they are on the edge of functionality, so everything has to be just right.
@@TechIngredients Cool! Any plans to make a DIY Ti:Sapphire? :) There are low-cost Chinese suppliers for the laser rods and dielectric mirrors, but knowing practical rod parameters (dopant concentration, geometry, FOM, etc.) for something that will lase with minimum trouble is difficult; the literature is very theoretical and academic (and of course commercial laser manufacturers don't want to tell you).
