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ArcticMyst Security by Avery

A new way to make laser-like beams using 250x less power






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Very cool, thanks for the link. I wonder what exactly this quasi-laser output would look like- maybe somewhere between an LED and a laser? Either way, I bet that it would be be pretty darn near perfect for video projectors, assuming the output wavelength is in 440nm range (unless theres some magical property of this specific process that dictates otherwise :p).
 
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Might take ten years to see anything come of this breakthrough, took a long time to get to where we are now.
 
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The new prototype requires 250 times less electricity to operate than its conventional counterpart made of the same material.

Standard laser diodes are 10-60% efficient. You cannot possibly get more than "10x less electricity" until the output power has to be less as well.

Basic math says the figure is bullshit.
 

USAbro

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Standard laser diodes are 10-60% efficient. You cannot possibly get more than "10x less electricity" until the output power has to be less as well.

Basic math says the figure is bullshit.

You are right. It's simple. Conversion of energy from 1 type to another always is at least partially inefficient, and this method (electrons to photons) is especially inefficient.
 
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I wonder how they came up with that figure then.... time to write the author.

Edit: OK I wrote her along with a link to this thread.
 
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Her answer:

HI Chris,

Thanks for writing about this work. Had to check with the researchers here for a refresher to answer your question. Thomas Frost tells me this:


The 250x less power is referring to the threshold of the laser. In a traditional laser, there is a large 'threshold' to lasing so any power put into the system up to that current is effectively wasted, although the laser may be nearly 100% efficient above this 'threshold.' The polariton laser having a very low 'lasing threshold' meaning that you don't have to put much energy in to the system to start get coherent light out. The 10-60% efficiency quoted on the forum is referring to the overall efficiency (Laser power out/input electrical power) which counts the wasted energy below threshold and the potentially near perfect efficiency above threshold. Because polariton 'lasing' occurs due to a different physical phenomenon, what the 250x less power is referring to is that the polariton lasing occurs at 1/250th the current as the photon lasing threshold in the same device.

Nicole

Nicole Casal Moore
Public Relations Rep.
University of Michigan
 
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Nobody operates lasers at threshold, for exactly the reason she stated - it's inefficient. So they clearly used an irrelevant measurement to make a snappy headline and take advantage of those that don't know jack shit about efficiency.

Scumbags.
 
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The headline could just as well read "Researches find new way to make a coherent beam 250x less powerful than a laser" I guess the breakthrough here is in the fact that you can't make a 1 microwatt laser. The "using less power" part of the headline was a poor wording choice that makes most people think that it has something to do with efficiency.
 




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