These are just frequencies of light, but the subjective experience of them is so much more.
And the whole thing of my perception of "red" or what I call "red" could be very different to someone else's subjective perception. But we would both call it red and associate it with the same thing, fire, love, heat, danger etc.
eg. Before Orange, there was only shades of yellow or reds
* You can pack many more different colors into fiber optic communication lines. Every color carries a few tens of GHz in modulation, but the carrier light is in hundreds of THz; there's a ton of bandwidth not used between readily available colors.
* You can likely do interesting molecular chemistry by precisely adjusting laser light to the energy levels of particular bonds / electrons.
* Maybe you can precisely target particular wavelengths / absorption bands for more efficient laser cutting and welding, if these adjustable lasers can be made high-power.
But I will say that precise control of laser wavelength is critical to today’s communication technologies. I doubt their new techniques will be useless.
The substance is they've created a way to fabricate a device that can make the optical frequencies they wish. That is useful: it means a designer isn't limited to frequencies that are economic to generate with existing techniques, which is a constraint that lasers currently struggle with: low cost, compact, efficient laser sources (the kind that fit on a chip, and are fabricated by cost effective processes,) only exist for a limited number of frequencies.
The story is typical tech journalism pabulum, but the underlying paper does discuss efficiency. It's about what you'd expect: 35 mW -> 6 mW @ 485 nm, for example.
An obvious use case is multimode fiber communication: perhaps this makes it possible to use more frequencies for greater bandwidth and/or make the devices cheaper/smaller/more efficient. But there are other, more exotic things one might do when some optical frequency that was previously uneconomic becomes feasible to use at scale.
I have an application in mind for this technology outside of photonic computing. Again, it depends entirely on price, tunability, bandwidth of the profile, etc. My understanding of the photocomputing field is limited but I never thought the major issues were wavelength related? Maybe someone can educate me.
If anyone wants to send me one of these I would be pumped.
I wish we had a large laser manufacturing ability in the West. I would say 95% of lasers of all kinds are manufactured in China.
What should I have experienced?
if you do the exact right color you can make certain things melt very precisely.
A rainbow gives you both red and blue; mute everything else, and you'll get magenta. That's what magenta pigments do when illuminated by white light (which is a rainbow scrambled).
Here's a nice visualization of color perception (there are more modern ones, but we used the 1931 color space when I was working in the field). The horseshoe shape on the outside is the single wavelength colors.