Cooler Silicon Lasers Via Energy Harvesting

Light Licker writes "UCLA researchers have developed a way to cut power use and heat output from a silicon laser used for optoelectronics. Both have been problems because silicon absorbs too much light — producing high-energy free electrons that make heat. One of Intel's best silicon lasers produced 125 times more heat than usable light. The UCLA team added a diode to their laser which can harvest free electrons and use them to help power the circuit — simultaneously cutting heat output and power use."

Comments

Jeez, a little diode?

[Corpuscavernosa]

You'd think Intel would know that Radio Shack carries a wide variety...

Not expected?

[pclminion]

"It's a very clever approach," says Philippe Fauchet, an applied physicist at the University of Rochester in New York State. "I did not expect it at all, which is always a nice surprise."

An applied physicist "didn't expect" that an electric field would move the free electrons out of the way?

Re:Not expected?

[Ngarrang]

"It's a very clever approach," says Philippe Fauchet, an applied physicist at the University of Rochester in New York State. "I did not expect it at all, which is always a nice surprise."

An applied physicist "didn't expect" that an electric field would move the free electrons out of the way?

Even the best and brightest can sometimes forget the little things. You can get so focused on another aspect.

Re:Not expected?

[kestasjk]

Maybe he didn't expect that the diode would create the electric field, maybe it's hard to put a diode right next to the laser, or maybe he didn't think the free electrons would travel away so easily.

To me it sounds exactly like how photovoltaic cells work; a light beam gives an electron enough energy to dislodge it, and a diode forces the electron to jump through a few hoops to get back to where it started. At face value it's too obvious to not have been thought of before, so you can bet there's something NewScientist aren't covering well.

Re:Not expected?

[weir]

I agree the idea is clever. Essentially they are recycling heat generated as a "byproduct". I wish there were a better way to generate electricity directly from heat. Other than the two dissimilar metals method, thermovoltaics instead of photovoltaics. I wonder if they run into feedback issues. Electricity->heat-electricity->heat.

Innovation

[Manos_Of_Fate]

This just goes to show that even seemingly simple ideas can be powerful.

"Wide variety"

[TheReckoning]

You haven't been to a Radio Shack lately, have you? They have almost nothing.

"You've got questions, we've got Blank Stares"

Re:"Wide variety"

[Anonymous Coward]

"You've got questions, we've got Blank Stares" Or "You've got questions, we've got batteries".

Re:"Wide variety"

[Cristofori42]

As a former RadioShack employee (sorry to admit it) I have to say that the main reason for the decline in customer service is the way it's managed. I had to go to this all day training meeting one time and the entire 6+ hours was basically "SELL EVERYONE WHO CAN TALK A F****** CELL PHONE, OR ELSE!!!"
Also, they put all of the sales people on comission and judge your morality by how many freakin' cell phones you sell. Of course they're not going to know the ins and outs of different transistors and resistors and XLR (and yes, I know what that is) connectors are because they make about .00001 cents for selling ones of those, whereas if you sell a few cell phones in a day suddenly you're rolling in cash. Add this on top of managers who make you feel like you've just killed a flock of kittens if you don't offer 5 cell phones to the 90 year old lady who wanted a new hearing aid battery and the result is what you see today.

True, they have like 2 toggle switches...

[Corpuscavernosa]

True, I haven't been there in awhile...

From the Onion: Even CEO Can't Figure Out How Radio Shack Still In Business

does this mean

[zappepcs]

that the newest batch of CD players won't be hot enough to reveal the secret disc art on NIN's new CD?

Re:does this mean

[renoX]

Well, this could maybe reduce the heat generated by the laser diode itself (don't know if this improvement is applicable to this part), but there will still be the heat generated by the laser beam on the CD, which of course is lower but it'll still be there.

Re:Oblig.

[LordEd]

Look, its simple. If its an article about lasers, the oblig comment will involve how a cooler laser will make the shark more comfortable, not the overlords comment. The overlords comment is better saved for when somebody actually develops the shark-carrying robots that will destroy us all (using the 1,2,3:??,4:profit! model, of course).

Freakin' Sweet

[Steve-o-192.168]

I can't wait for my laser-beam eyes!

Re:Oblig.

[inviolet]

:golf clap:

Don't forget the obligatory reference to simply powering the laser with frozen nitrogen, to simultaneously power it and keep it cool and pop a ton of popcorn from the stratosphere.

Re:Oblig.

[kurzweilfreak]

And then don't forget the Beowulf cluster of them that uses frozen nitrogen to power you in Soviet Statosphere! Er... something like that.

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Hey, look over there, Natalie Portman! D'oh! *runs*

Re:Oblig.

[jcorno]

Don't forget the obligatory reference to simply powering the laser with frozen nitrogen, to simultaneously power it and keep it cool and pop a ton of popcorn from the stratosphere.

Um, it was frozen bromine in an argon matrix. Liquid nitrogen would have to be frozen in helium, which just doesn't make sense.

Not so obvious

[BlueParrot]

All you people who wonder how one could have missed something so obvious, well, it isn't obvious. Firstly, what actually happens inside a solid-state laser is an absolute pain to work out rigorously. The quantum mechanics involved is sufficiently complicated that the preferred method of finding a good lasing material is pretty much trial and error. You are talking about systems where adding a few fractions of a percent of impurities changes the energy levels, and consequentially the physical properties of your semi-conductor. Changing the temperature at which you grow your silicon crystal, or at what rate you cool it, or how you add the doping material, or weather the moon is in the seventh phase, can have implications for how these things work. You are dealing with processes that occur at nanometer length scales, where you can't just fit things together using a bit of duct tape and a can of WD40 ( tho don't quote me on that, because it is just far too likely that someone crazy enough will find a way to use WD40 in a laser ).

What I'm trying to say is that sticking a diode to your home made radio circuit is one thing, finding a way to do it to a laser based on an ultra-pure silicon crystal, which changes its behavior if you do anything more severe than to think about it is hard (and keep in mind, this is QM we are talking about, chances are thinking about it does in fact kill the cat... ). My experience with solid state physics is rather limited, but I know one thing. It sure as hell isn't obvious... (If you doubt it, go look up the explanation for why gallium arsenide makes better photo voltaic cells than silicon).