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NIST scientists create 'any wavelength' lasers

nist.gov

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Re: NIST scientists create 'any wavelength' lasers

#191

Post by sbuttgereit »

nabakin wrote: post #59

> When it comes to information transfer and processing, light can do things that electricity can’t. Photons — particles of light — are far zippier than electrons at working their way through circuits. Electrons themselves don't move at the speed of light, but information transfer (i.e. communication) via electrons does happen close to the speed of light. A subtle, but important, distinction that's often misunderstood…

Looking at the discussion below this comment, I'd just add this video by AlphaPheonix:

https://www.youtube.com/watch?v=2Vrhk5OjBP8

Good discussion in the comments there as well.

Re: NIST scientists create 'any wavelength' lasers

#192

Post by dnnddidiej »

thaumasiotes wrote: post #189
dnnddidiej wrote: post #80

Earlier quoted context omitted.

I haven't heard of a wavelength of 2 frequencies merged. It is like saying what is the wavelength if you tune to 2 radio stations with 2 radios (assume silent transmition for simplicity). There are 2 wavelengths.

> I haven't heard of a wavelength of 2 frequencies merged. It is like saying what is the wavelength if you tune to 2 radio stations with 2 radios No, any wave has a wavelength. You can add sin(3x) to sin(2x) and the resulting wave is a perfect fifth. Its wavelength is determined by its components; since sin(2x) has a wavelength of π and sin(3x) has one of 2π/3, the combined wave will have one of 2π. The difference is…

Thanks, interesting!

Re: NIST scientists create 'any wavelength' lasers

#193

Post by joquarky »

rafram wrote: post #61
nine_k wrote: post #49

Earlier quoted context omitted.

It's called orange. Much like bright gray is called white, and bright teal is called turquoise.

Light brown is called tan. Dark and light oranges exist too and they’re not exactly the same as brown.

Tan is not a hue. Orange is.

Re: NIST scientists create 'any wavelength' lasers

#194

Post by smallerize »

ledoge wrote: post #119
smallerize wrote: post #98

Earlier quoted context omitted.

That sounds cool but how do you encode the image data?

That's the easy part, just use a color space with imaginary primaries (see e.g. ProPhoto RGB), or use one with real primaries that allows for negative values – e.g. Windows uses floating point scRGB for HDR, which is just linear BT.709/sRGB, but negative RGB values can be used to cover the full range of real and imaginary colors.

But that's still mixing just a few primary wavelengths.

Re: NIST scientists create 'any wavelength' lasers

#195

Post by jagged-chisel »

tclancy wrote: post #90
jagged-chisel wrote: post #43

The "shrinking" circle: I did as asked and clicked the image to see the animation. I saw no shrinking. My eyes did fatigue and I saw the border between the red and green become a blurred gradient. What should I have experienced?

You have to not blink too much or it resets the effect. After about a minute, the intense blue shows up around the red. And I say that as a man who has yet to see anything in a Magic Eye poster after a half century of what some would call life.

I also lack stereopsis- those posters are always just noise to me. I always wonder whether some of these visual tests only work on those with normal stereo perception.

Re: NIST scientists create 'any wavelength' lasers

#196

Post by hank808 »

hank808 wrote: post #77
TomatoCo wrote: post #64

Earlier quoted context omitted.

It reminds me of how vinyl records are fairly lossy, but they provide a superior experience in some cases because those limitations have been accounted for during the mastering process. It's an entire pipeline from photomultiplier to recording medium to the inverse process and everything is optimized not for any particular mathematical truth but for the subjective experience.

Most records these days use CDs as masters, sadly.

No. A friend of mine worked at United Record Pressing. The majority of the masters they received from customers were commercial CDs. No special master.

Re: NIST scientists create 'any wavelength' lasers

#197

Post by summa_tech »

nine_k wrote: post #169
summa_tech wrote: post #60

Earlier quoted context omitted.

Fiber has fairly narrow windows in which it is as transparent as it needs to be to go long distance. We're already pretty good at filling these windows with conventional semiconductor lasers. What this is actually interesting for is being able to access arbitrary atomic transitions, many of which are outside the range of conventional semiconductors (too short, usually - there's a big hole between green and red for se…

This is true. But even within this window, e.g. between 1100 nm infrared and 700 nm red, we could put 40 different "colors" at 10 nm steps. Separation at the receiving end may become hard though.

Standard ITU grid is 100 GHz channel spacing, with subdivisions of 25 and 50. We're routinely using symbol rates high enough that the channels are fairly well filled.

Re: NIST scientists create 'any wavelength' lasers

#198

Post by IAmBroom »

dotancohen wrote: post #126
wdutch wrote: post #115

Earlier quoted context omitted.

When I was young I was taught that pink is a light shade of red. But what kids these days call pink seems to me to be a bright magenta.

The word "pink" is derived from a name this flower had about 600 years ago: https://upload.wikimedia.org/wikipedia/commons/4/42/Dianthus... So however you see that flower, that's the literal pink prototype.

And the flower is named for its "cutmarks" on its petal edges, which resemble pinking on cut fabric.

Re: NIST scientists create 'any wavelength' lasers

#199

Post by IAmBroom »

analog31 wrote: post #89
adzm wrote: post #24

Everyone talking about magenta and brown, but you can see an illusory color right now even without lasers! https://dynomight.net/colors/ behold, some kind of hyper-turquoise

I worked with a brown laser when I was in grad school. It made a couple of brown spots on the wall by accident.

Are you sure you weren't just squeezing a dispeptic mouse too hard?

Re: NIST scientists create 'any wavelength' lasers

#200

Post by momoschili »

MeteorMarc wrote: post #141
momoschili wrote: post #134

Earlier quoted context omitted.

I don't think so- seems like they demonstrated a supercontinuum source, which is a pretty good approximation of "any wavelength" laser. Pretty cool on an integrated chip.

Where is the source? Tantalo does not produce photons, it is not like GaAs that you can pump and get stimulated emission. The Nature paper does not have laser in the title.

its purpose isn't to produce photons, neither is the lithium niobate. The purpose is act as a material to mediate the nonlinear interactions between photons to achieve fun things like supercontinuums, frequency comb generation, etc.

Think of it like the phosphor on your white LED - it produces no photons by itself, but it takes in the blue photons and remits them in a different spectrum. Obviously different physics, but still a similar concept.

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