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NIST scientists create 'any wavelength' lasers

nist.gov

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Re: NIST scientists create 'any wavelength' lasers

#141

Post by MeteorMarc »

momoschili wrote: post #134
MeteorMarc wrote: post #132

Title is misleading. This is about integrated optics that can do "computation" on the frequency of laser input using all kinds of nonlinear optical effects.

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.

Re: NIST scientists create 'any wavelength' lasers

#142

Post by swiftcoder »

14 wrote: post #95
jcul wrote: post #42

Earlier quoted context omitted.

The whole idea of colour and light frequency is fascinating. 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.

I have thought about this before as well. Like maybe what I see as red you see as purple but since we have always been taught that what we both see is red to both of us it is red. I am however leaning more to the belief that typically we all see colors the same. But it is one of those things that could never be proven. Another interesting thought that comes to mind speaking about color perceptions is I recently read…

> I am however leaning more to the belief that typically we all see colors the same.

Some of us explicitly don't see colour the same - I'm partially colourblind, and have pretty concrete evidence that I don't see colour that same way the average person does.

Turns out that while we tend to assign a binary colourblind/not-colourblind threshold to this, in practice humans exist along more of a spectrum of colour acuity (not to mention there are half-a-dozen distinct variants of colourblindness)

Re: NIST scientists create 'any wavelength' lasers

#143

Post by dtgriscom »

That picture of the wafer with a rainbow of shapes is very misleading. It suggests that the various colors you see on the chip is the various colors the lasers can emit, which is wrong; it's just diffraction, and has nothing to do with the topic of the article. (But, PR people gotta PR...)

Re: NIST scientists create 'any wavelength' lasers

#145

Post by notahacker »

XorNot wrote: post #114
com2kid wrote: post #82

Earlier quoted context omitted.

Vinyls are sometimes preferred because people like white noise, same as tube amps. Granted some CDs are mastered like garbage, and that led to some bad press for awhile. But you can master a CD so that it sounds exactly, as in mathematically exactly, as a vinyl record, if so desired. It is also possible to make a digital amplifier that sounds exactly identical to vacuum tubes. Humans have well and mastered the art of…

I mean I've always thought the kinetic experience of vinyl was the point: my childhood memory is the excitement and anticipation of carefully putting the needle on the lead in and hearing the subtle pops and scratches that meant it was about to start. The whole physical enterprise has a narrative and anticipation to it.

Not to mention the wider context of starting off by opening a beautifully designed record sleeve, and the chances people choosing to listening to vinyl are doing so on a beautifully engineered soundsystem that cost as much as a car when it was released 50 years ago, or a turntable setup that's designed for them to interact with.

Re: NIST scientists create 'any wavelength' lasers

#146

Post by KK7NIL »

xbmcuser wrote: post #144

Is this the cheaper way to get to extreme uv lithography as from what I understand the largest bottle neck for China has been to get the exact wavelength needed to go small enough?

No, the problem is getting a high power (hundreds of watts) and high uptime EUV source, there's no reason to think this is a step towards that at the moment.

Re: NIST scientists create 'any wavelength' lasers

#147

Post by KK7NIL »

tempaccount5050 wrote: post #122
NL807 wrote: post #113

Earlier quoted context omitted.

In electric circuits, information is transmitted through the electric field, which itself is close to the speed of light.

Nope, it's 1/2 - 2/3 the speed of light depending on the metals used.

The velocity factor is usually 0.6-0.7, never seen it as low as 0.5.

And it's set by the dielectric, not the conducting material.

Re: NIST scientists create 'any wavelength' lasers

#148

Post by phrotoma »

jcul wrote: post #42
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

The whole idea of colour and light frequency is fascinating. 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.

I have seen Wiggtenstein's language games invoked to explain this "your red isn't my red" possibility, but I've never really been able to follow the reasoning.

Perhaps some philosophically inclined HNer who passes by here can let me know if this is a legit application of his ideas?

Re: NIST scientists create 'any wavelength' lasers

#149

Post by nkrisc »

d0mine wrote: post #107
da_chicken wrote: post #55

Earlier quoted context omitted.

I think it's important to remember that we're not perceiving some fundamental aspect of light. We're perceiving how the photosensitive portions of our retina convert light to stimulus, and how our brains construct a meaningful image from that stimulus in our mind. Like film photography doesn't happen in the lens or the world. It happens in that photosensitive chemical reaction, and the decision of the photographer.

> how our brain construct is the only part i.e., we perceive what brain predicts no more no less. Optical illusions demonstrate it well. Sometimes that prediction (our perception) correlates with the light reaching the retina. But it is a mistake to think that we can perceive it directly. For example, we do not see the black hole in our field of vision where there are no receptors (due to our eyes construction). Anot…

It’s an important point: all our sensations are interpretations of readings from various sensing abilities.

Which is why it can be so easy to produce false sensations of many things. It’s like tricking your fridge into turning the light off by pressing the little switch instead of closing the door. The fridge isn’t detecting when the door is closed, it’s detecting with that switch is pressed and interpreting that as meaning the door is closed. However that interpretation may not always be correct.

Re: NIST scientists create 'any wavelength' lasers

#150

Post by ChrisMarshallNY »

da_chicken wrote: post #55
jcul wrote: post #42

Earlier quoted context omitted.

The whole idea of colour and light frequency is fascinating. 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.

I think it's important to remember that we're not perceiving some fundamental aspect of light. We're perceiving how the photosensitive portions of our retina convert light to stimulus, and how our brains construct a meaningful image from that stimulus in our mind. Like film photography doesn't happen in the lens or the world. It happens in that photosensitive chemical reaction, and the decision of the photographer.

If you pay attention to cats, you figure out they are fuzzy little “difference engines.” They seem to be hyper-tuned to things that change.

For example, if I move a small item in the corner of my room, the next time the cat walks in, he’ll go straight to it, and sniff around.

I have a feeling that cat’s eyes have some kind of “movement sensors,” built in. Maybe things that move look red, and most of the background looks grey.

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