Flying saucer; quantum dots hold secret to brighter, better lasers

[steve001]

https://phys.org/news/2017-03-saucer-quantum-dots-secret-brighter.html

 

[Alaskan]

Nice, thank you

Quantum dots are well-known bright light emitters," says Alex Voznyy, a senior research associate in Sargent's lab. "They can absorb a lot of energy and re-emit it at a particular frequency, which makes them a particularly suitable material for lasers."

Read more at: https://phys.org/news/2017-03-saucer-quantum-dots-secret-brighter.html#jCp

 

[BowtieGuy]

Very interesting, a "quantum dot" tunable laser may be the future! :yh:
Thanks for sharing Steve.

 

[paul1598419]

That was interesting, but seems to be something that may happen years from now. Still, I never pass up knowledge, especially in physics.

 

[WizardG]

"watts" and "tunable" I certainly like hearing those two words together. Now if they would go together in a handheld.......

 

[Benm]

Don't hold your breath

With optically pumped quantum dots you cannot achieve population inversion, so there is no way to make lasers out of those, even if they make commercially viable backlights for tv's and such.

IF they could somehow be electricallly pumped directly that could be a game changer in the future, but we are not there yet by a long shot.

 

[WizardG]

Don't hold your breath

With optically pumped quantum dots you cannot achieve population inversion, so there is no way to make lasers out of those, even if they make commercially viable backlights for tv's and such.

The article claims they've been able to coax short pulses of laser output from quantum dots for years, just not easily or efficiently. And these oblate shpheroid dots are capable of CW lasing via optical pumping.

IF they could somehow be electricallly pumped directly that could be a game changer in the future, but we are not there yet by a long shot.

The article states they're working on electrical pumping. Not holding my breath, but certainly wishing them (and us!) the best of luck.

 

[CurtisOliver]

I sure do hope that one day we will have them in our hands. Electrical pumping quantum dots sounds rather interesting. Thanks for sharing Steve. :beer:

 

[steve001]

You're all welcome.

 

[BobMc]

https://phys.org/news/2017-03-saucer-quantum-dots-secret-brighter.html

I want one in a handheld.

 

[Benm]

Who knows Once they get it to work it could become pretty compact.

As long as you can get electrical pumping or some other mechanism to achieve population inversion there is no reason these cannot be used as a laser medium. It could be a way to close the 'color gap' by providing lasers that are efficient and produce, for example, yellow light.

 

[CurtisOliver]

Now that sounds exciting. If they do, then the forum could see plenty of new wavelengths in the future.

 

[Benm]

It would. In fact, i'm surprised that we don't have a much wider range of diode laser colors available right now.

Apparently creating different wavelength diode lasers has been quite difficult, even green ones. The 510-520 nm variety is a pretty recent development (at least commercially) and is very usefull to create all-direct-diode RGB projectors and such.

I think the commercial interest in creating a yellow laser diode is much lower, though it could be very useful to increase the brightness of projections, if it could be easily mixed with other colors (needs an extra dichro, adjust and and all).

 

[HydroSean]

sounds like promising research, if they do scale it up right we might have better beam specs with these than our best high powered single modes.

 

[steve001]

It would. In fact, i'm surprised that we don't have a much wider range of diode laser colors available right now.

Apparently creating different wavelength diode lasers has been quite difficult, even green ones. The 510-520 nm variety is a pretty recent development (at least commercially) and is very usefull to create all-direct-diode RGB projectors and such.

I think the commercial interest in creating a yellow laser diode is much lower, though it could be very useful to increase the brightness of projections, if it could be easily mixed with other colors (needs an extra dichro, adjust and and all).

There are applications for yellow lasers, but such lasers fall into what is called the "Green Gap". It's at this point in time a difficult challenge to make diodes that lase at wavelenghts greater than >536nm.

 

[CurtisOliver]

I know, the lime green/yellow band is stuck in the middle of two diode mediums. InGan/GaN doesn't like to lase high and AlGaInP doesn't like to lase too low.
We need a new semiconductor for the rest of the spectrum, unless we get these quantum dots lasing of course.