The terminology is all wrong for the University of Virginia underclassmen. UVa has neither freshmen nor seniors, but rather first years and fourth years, since Thomas Jefferson believed that no student is a senior of knowledge after 4 years.
The promise of making a laser from indirect bandgap semiconductors, then gathering investors, then losing the investors' money goes back to the Sixties at least.
Some scientists showed off SiC blue LEDs in the '60s that shown brilliantly like laser light, but were not the read deal. The real blue room-temperature laser had to wait for Nakamura and a direct bandgap material.
Doping, adding nitrogen, and adding defects to the lattice to produce more light is nothing new. Look at your stop lights. It's working there, but don't count on these indirect materials suddenly turning into lasers. No need to hold your breath.
A quick scientific note. Photons have a lot of energy, but not much momentum. You get hot on a sunny day, but not blown over by the sun. Electrons fall almost directly down in the bandgap diagram to produce light. This makes direct-gap semiconductors useful for lasers. The trick one can use is to provide momentum-shifting impurities to the lattice of an indirect bandgap crystal. The electron creates a photon by dropping directly down, but some other mechanism shifts the electron momentum to create an overall diagonal transition. It's not efficient, but it works.
I have a Ph.D. in semiconductor physics. I worked in one of the labs mentioned in the article. I have to tell you that the description in Nature is really inaccurate. What the Russian likely did is luminesce off a trap in SiC, not off the full bandgap. SiC is not even a direct-bandgap crystal. Yes, it produces blue-green light. It is a point-contact diode, but it is NOT an LED. Nothing practical or useful existed until Nick Holonyak made the first visible LED, then the first visible LED laser a few months later. Bob Hall made the first LED laser. There were a bunch of guys with Ge infrared-emitting diodes before 1962, but history forgets these guys rightly. Both the SiC and Ge diodes are such poor light emitters, that they should not be considered LEDs.
Another interesting moment I believe was in the 1960s. Researchers in America claimed to have a working, continuous, non-pulsed room temperature SiC laser. It looked like beautiful blue laser light, but it was a big bust. It was not a laser. Just like this Russian, there was nothing useful going on in SiC.
THANK YOU for your submission of a new
[x] nanostructure
[ ] laser
[x] transistor
using
[x] large molecules
[ ] DNA strands
[ ] silicon
This is a bad idea, because
[ ] a 3-D structure is difficult to heat-sink
[x] scientists likely never will produce a transistor this way
[x] silicon has unique properties that cannot be matched
[ ] this is a case of outright fraud
The problem however is not to make circuits
[ ] out of lasers
[ ] 3-D
[x] from anything but silicon
[ ] self ordered
But the problem is to make them
[x] reliably
[x] at low cost
[x] faster
Further this article was published in
[ ] Science
[ ] New Scientist
[x] NYT
[ ] Science News
which is primarily a publicity-seeking instrument, and not a great peer-reviewed journal of physics.
I can say this because I have a
[ ] BS
[ ] MS
[x] PhD
in
[x] Physics
[ ] Electrical Engineering
THANK YOU for your submission of a new
[x] nanostructure
[ ] laser
[ ] transistor
using
[ ] straw and bailing wire
[x] DNA strands
[ ] silicon
This is a bad idea, because
[x] a 3-D structure is difficult to heat-sink
[x] scientists likely never will produce a transistor this way
[ ] this is a case of outright fraud
The problem however is not to make circuits
[ ] out of lasers
[x] 3-D
[x] self ordered
But the problem is to make them
[x] reliably
[x] at low cost
[x] faster
Further this article was published in
[ ] Science
[ ] New Scientist
[ ] Nature
[x] Science News
which is primarily a publicity-seeking mag, and not a great peer-reviewed journal for physics.
I can say this because I have a
[ ] BS
[ ] MS
[x] PhD
in
[x] Physics
[ ] Electrical Engineering
From TFA: Posted by wss at October 4, 2005 08:40 AM
Which means that the news is 22 days old. Given that this is a monthly survey, the slashpost seems a tad bit behind the times.
One of us should write a bot that posts a story 21 days after the fact and see if we can beat the masses that happen upon Netcraft and re-print old news.
For one, it's first-gen stuff. It will likely gain density quickly in the future.
It may gain density, but gain little in reliability. I have a Ph.D. in solid state physics, so I should respond. The carbon nanotubes bend to make connect with an electrode, so something moves. This is usually a bad sign for long-term reliability. Ask telecom technicians if they would like to replace their solid state transistor-based switches with moving switches. Their answer will be that these moving parts wore out.
This memory might not improve to the point that it becomes more reliable than your present NVRAM.
It is very easy for a scientist to produce one working device in the lab. We call these hero devices. The rest of the world does not know this. When engineers get ahold of these claims, though, they tear them up, since the process might not be cheap, reliable or scaleable.
So yes, it might get better, but I wonder if this group and the related scientist have invented new physics. Have they fundamentally changed the way mechanical switches make contact, the way electrons move and are held in capacitors, and the way domains set up in magnetic memory? I think not. I think this is a step backwards towards old mechanical swithces made smaller and reliable memory made unreliable.
Jack Kilby is said to have invented the integrated circuit. This is not entirely correct for three reasons.
1) Jack Kilby simply jumpered wires around a semiconductor. At the same time and before at Fairchild, Bob Noyce produced a planar process that we use today. Subsequently, TI used Noyce's process, not Kilby's.
2) A lawyer at TI argued for years that Jack Kilby invented the IC. Fairchild was awarded the first patent for the IC, but eventually gave up. Since the lawyer won the case despite all of the evidence against Kilby, the Nobel committee should have included the lawyer in the Nobel prize. He is partly responsible for it.
3) If Intel (the eventual home of Noyce) were to claim that Noyce invented the IC, it would have given an expensive gift to Fairchild. Fairchild at one point could have sued Intel for all Noyce walked out with. It would create a mess. TI claimed all along that Kilby invented the IC. Corporate publicity won the day.
The CO2 concentration was 7000 ppm during the Cambrian period, 500 million years ago. Was this a time of mass extinction? Not at all. During the Cambrian Explosion, your relatives started having sex, and evolved into animals at a tremendous rate.
What is the carbon concentration now? A measly 350-380 ppm.
What does this low rate mean. MASS EXTINCTIONS!
Or does it?
Let's recap:
350 ppm CO2 = MASS EXTINCTIONS!
7000 ppm CO2 = A pretty good time for evolution.
1) Wavelengths are too big: 1 micron is now a large number, and optics doesn't work much smaller than this.
This poster is correct. Since I have a Ph.D. in the field and the parent obviously knows something about optics, I might as well respond to the parent's critics.
IR photons are BIG. Forcing light to bend around corners is difficult. A waveguide must have a very high index of refraction if it is to be used to bend light within a reasonable radius. To the extent a Bose-Einstein Condensate helps this problem is encouraging if you don't mind cooling your computer to 2 millikelvin.
The speed of these optical computers always seems to come down to limitations of the silicon processors that work in conjunction with the light.
It's just a Bose-Einstein Condensate. These projects take time. While we are enamored with this BEC project, some poor grad student is working on carbon doping. Higher doping might improve the world of electronics far more than another optical computer claim.
I visited Hau's website and did, though, enjoy her papers. I just don't think the press release accurately portrays the low engineering potential of this work.
I worked with Milton Feng, the professor who did this work, at the University of Illinois. His work is very good. In grad school, his thesis advisor's advisor's advisor was the co-inventor of the transistor. (I say co- because William Shockley was in Europe when the transistor was invented.)
His advisor's advisor invented the LED.
His advisor worked on early technology for the HBT that Milton studies.
As mentioned earlier on slashdot, these are not transistors for processors. Better than that, parts of this technology can lead to better III-V based technology.
OS, Web Server and Hosting History for www.yankeegroup.com
http://www.yankeegroup.com was running Microsoft-IIS on Windows 2000 when last queried at 3-Apr-2005 19:35:06 GMT
It seems yankeegroup.com puts their money where their mouth is. Maybe it is not so bad that they use a security risk as an OS. Maybe the 500 technology leaders chose better than the rest of us. There must be something this lady can find that is positive about Linux. I never see her kind remarks for what is a favorite for many, many companies for TCO and reliability.
The company claims that its optical modulator for transforming electrons into photons runs at 10-GHz
I may not have a Nobel Prize, but I do have a Ph.D. in physics. Electrons do not tranform into photons. They may produce photons, but not turn into them.
I see these articles that claim the creation of optical processors. But read the article, and all the researchers have to do is add a silicon processor and BOOM, we have an optical processor. It's not that easy.
I remember the researcher who created an optical computer that was the size of a room. Why is this? Electrons are small. They bend around corners. They stay put. They move when you want them to. Photons do not bend well around small corners, do not support CMOS-like circuits and generally fail at most tasks of that versatile, tiny doer of great deeds, the electron.
As usual, it's just an optical modulator. Boring old modulator.
(2) Open
\Documents and Settings\YOURUSERNAME\Application Data\Mozilla\Firefox\Profiles\default.XXX\compreg. dat
in your favorite ascii editor.
(3) Search for 'idn' in Note/Wordpad. Comment out with a '#' the line that says "{NUMBERSLETTERSDASHES},@mozilla.org/network/idn - service;1..." to become
"#{NUMBERSLETTERSDASHES},..."
I just returned from the supposedly closed China, and have much to say that contradicts the article. Most of the article plays on the ignorance of Westerners.
The internet cafes were cheap (around $1 for 4-8 hours) and usually a bit dirty. I was blocked from no site except the San Jose Mercury News, and the site was back online in China the next time I checked. It was not the "Great Fire Wall of China" in action. There have got to be more than 100,000 internet cafes. They're on many, many street corners. Some are built with sleeping quarters attached. Maybe there are 100,000 registered internet cafes, but who really registers anything in China?
I am sure many who live in English speaking countries read these things imagine laws might be followed and enfoced like they are in the UK and US. Strict laws require some enforcement. From what I saw and heard and contrary to what I read from the Chinese press, there was hardly a hint of control over the millions of teenagers online.
If Chinese people are kept in the dark, it seems only to be about their own country (about SARS, e.g.). They often know many details about the U.S., including sports scores, movies and news.
H.J. Round (1907) is credited, somewhat correctly with the invention of the blue-green LED.
See
this
I think real blue LEDs came about in the '60s.
Nakamura's great contribution was to use lateral overgrowth to produce the first practical blue laser. In engineering, people get more credit for practicality than first display of a principle.
I read the Nature article on which the link was based, and the linked article is dead wrong. It is not an all-silicon laser, since it requires another laser to run. Worse than that, it appears to be close to a silicon optical switch, which can be modulated at a high rate.
The Nature article called it a "High Speed Silicon Optical Modulator," and "optical modulator" != "laser"
If these guys had produced an electically-driven continuous-wave silicon laser, they should get a Nobel Prize. Instead it looks like a rehashing of well-known principles to sound better in a slick-looking, flawed article.
Slashdot Mirror
The terminology is all wrong for the University of Virginia underclassmen. UVa has neither freshmen nor seniors, but rather first years and fourth years, since Thomas Jefferson believed that no student is a senior of knowledge after 4 years.
The promise of making a laser from indirect bandgap semiconductors, then gathering investors, then losing the investors' money goes back to the Sixties at least.
Some scientists showed off SiC blue LEDs in the '60s that shown brilliantly like laser light, but were not the read deal. The real blue room-temperature laser had to wait for Nakamura and a direct bandgap material.
Doping, adding nitrogen, and adding defects to the lattice to produce more light is nothing new. Look at your stop lights. It's working there, but don't count on these indirect materials suddenly turning into lasers. No need to hold your breath.
A quick scientific note. Photons have a lot of energy, but not much momentum. You get hot on a sunny day, but not blown over by the sun. Electrons fall almost directly down in the bandgap diagram to produce light. This makes direct-gap semiconductors useful for lasers. The trick one can use is to provide momentum-shifting impurities to the lattice of an indirect bandgap crystal. The electron creates a photon by dropping directly down, but some other mechanism shifts the electron momentum to create an overall diagonal transition. It's not efficient, but it works.
Yes, it is from 1997, but still true.
'Knuth acknowledged he was paid a "seven-figure sum" from Microsoft, which he will use to finance his work on a project he has code-named "Volume 4".'
http://www.panix.com/~clp/humor/computers/microsoft/TeX.html
I have a Ph.D. in semiconductor physics. I worked in one of the labs mentioned in the article. I have to tell you that the description in Nature is really inaccurate. What the Russian likely did is luminesce off a trap in SiC, not off the full bandgap. SiC is not even a direct-bandgap crystal. Yes, it produces blue-green light. It is a point-contact diode, but it is NOT an LED. Nothing practical or useful existed until Nick Holonyak made the first visible LED, then the first visible LED laser a few months later. Bob Hall made the first LED laser. There were a bunch of guys with Ge infrared-emitting diodes before 1962, but history forgets these guys rightly. Both the SiC and Ge diodes are such poor light emitters, that they should not be considered LEDs. Another interesting moment I believe was in the 1960s. Researchers in America claimed to have a working, continuous, non-pulsed room temperature SiC laser. It looked like beautiful blue laser light, but it was a big bust. It was not a laser. Just like this Russian, there was nothing useful going on in SiC.
THANK YOU for your submission of a new
[x] nanostructure
[ ] laser
[x] transistor
using
[x] large molecules
[ ] DNA strands
[ ] silicon
This is a bad idea, because
[ ] a 3-D structure is difficult to heat-sink
[x] scientists likely never will produce a transistor this way
[x] silicon has unique properties that cannot be matched
[ ] this is a case of outright fraud
The problem however is not to make circuits
[ ] out of lasers
[ ] 3-D
[x] from anything but silicon
[ ] self ordered
But the problem is to make them
[x] reliably
[x] at low cost
[x] faster
Further this article was published in
[ ] Science
[ ] New Scientist
[x] NYT
[ ] Science News
which is primarily a publicity-seeking instrument, and not a great peer-reviewed journal of physics.
I can say this because I have a
[ ] BS
[ ] MS
[x] PhD
in
[x] Physics
[ ] Electrical Engineering
THANK YOU for your submission of a new
[x] nanostructure
[ ] laser
[ ] transistor
using
[ ] straw and bailing wire
[x] DNA strands
[ ] silicon
This is a bad idea, because
[x] a 3-D structure is difficult to heat-sink
[x] scientists likely never will produce a transistor this way
[ ] this is a case of outright fraud
The problem however is not to make circuits
[ ] out of lasers
[x] 3-D
[x] self ordered
But the problem is to make them
[x] reliably
[x] at low cost
[x] faster
Further this article was published in
[ ] Science
[ ] New Scientist
[ ] Nature
[x] Science News
which is primarily a publicity-seeking mag, and not a great peer-reviewed journal for physics.
I can say this because I have a
[ ] BS
[ ] MS
[x] PhD
in
[x] Physics
[ ] Electrical Engineering
From TFA:
Posted by wss at October 4, 2005 08:40 AM
Which means that the news is 22 days old. Given that this is a monthly survey, the slashpost seems a tad bit behind the times.
One of us should write a bot that posts a story 21 days after the fact and see if we can beat the masses that happen upon Netcraft and re-print old news.
For one, it's first-gen stuff. It will likely gain density quickly in the future.
It may gain density, but gain little in reliability. I have a Ph.D. in solid state physics, so I should respond. The carbon nanotubes bend to make connect with an electrode, so something moves. This is usually a bad sign for long-term reliability. Ask telecom technicians if they would like to replace their solid state transistor-based switches with moving switches. Their answer will be that these moving parts wore out.
This memory might not improve to the point that it becomes more reliable than your present NVRAM.
It is very easy for a scientist to produce one working device in the lab. We call these hero devices. The rest of the world does not know this. When engineers get ahold of these claims, though, they tear them up, since the process might not be cheap, reliable or scaleable.
So yes, it might get better, but I wonder if this group and the related scientist have invented new physics. Have they fundamentally changed the way mechanical switches make contact, the way electrons move and are held in capacitors, and the way domains set up in magnetic memory? I think not. I think this is a step backwards towards old mechanical swithces made smaller and reliable memory made unreliable.
Jack Kilby is said to have invented the integrated circuit. This is not entirely correct for three reasons.
1) Jack Kilby simply jumpered wires around a semiconductor. At the same time and before at Fairchild, Bob Noyce produced a planar process that we use today. Subsequently, TI used Noyce's process, not Kilby's.
2) A lawyer at TI argued for years that Jack Kilby invented the IC. Fairchild was awarded the first patent for the IC, but eventually gave up. Since the lawyer won the case despite all of the evidence against Kilby, the Nobel committee should have included the lawyer in the Nobel prize. He is partly responsible for it.
3) If Intel (the eventual home of Noyce) were to claim that Noyce invented the IC, it would have given an expensive gift to Fairchild. Fairchild at one point could have sued Intel for all Noyce walked out with. It would create a mess. TI claimed all along that Kilby invented the IC. Corporate publicity won the day.
The CO2 concentration was 7000 ppm during the Cambrian period, 500 million years ago. Was this a time of mass extinction? Not at all. During the Cambrian Explosion, your relatives started having sex, and evolved into animals at a tremendous rate.
What is the carbon concentration now? A measly 350-380 ppm.
What does this low rate mean. MASS EXTINCTIONS!
Or does it?
Let's recap:
350 ppm CO2 = MASS EXTINCTIONS!
7000 ppm CO2 = A pretty good time for evolution.
1) Wavelengths are too big: 1 micron is now a large number, and optics doesn't work much smaller than this.
This poster is correct. Since I have a Ph.D. in the field and the parent obviously knows something about optics, I might as well respond to the parent's critics.
IR photons are BIG. Forcing light to bend around corners is difficult. A waveguide must have a very high index of refraction if it is to be used to bend light within a reasonable radius. To the extent a Bose-Einstein Condensate helps this problem is encouraging if you don't mind cooling your computer to 2 millikelvin.
The speed of these optical computers always seems to come down to limitations of the silicon processors that work in conjunction with the light.
It's just a Bose-Einstein Condensate. These projects take time. While we are enamored with this BEC project, some poor grad student is working on carbon doping. Higher doping might improve the world of electronics far more than another optical computer claim.
I visited Hau's website and did, though, enjoy her papers. I just don't think the press release accurately portrays the low engineering potential of this work.
I worked with Milton Feng, the professor who did this work, at the University of Illinois. His work is very good. In grad school, his thesis advisor's advisor's advisor was the co-inventor of the transistor. (I say co- because William Shockley was in Europe when the transistor was invented.)
His advisor's advisor invented the LED.
His advisor worked on early technology for the HBT that Milton studies.
As mentioned earlier on slashdot, these are not transistors for processors. Better than that, parts of this technology can lead to better III-V based technology.
From Netcraft in a query of www.yankeegroup.com:
OS, Web Server and Hosting History for www.yankeegroup.com
http://www.yankeegroup.com was running Microsoft-IIS
on Windows 2000 when last queried at 3-Apr-2005 19:35:06 GMT
It seems yankeegroup.com puts their money where their mouth is.
Maybe it is not so bad that they use a security risk as an OS. Maybe the 500 technology leaders chose better than the rest of us. There must be something this lady can find that is positive about Linux. I never see her kind remarks for what is a favorite for many, many companies for TCO and reliability.
From the Article:
The company claims that its optical modulator for transforming electrons into photons runs at 10-GHz
I may not have a Nobel Prize, but I do have a Ph.D. in physics. Electrons do not tranform into photons. They may produce photons, but not turn into them.
I see these articles that claim the creation of optical processors. But read the article, and all the researchers have to do is add a silicon processor and BOOM, we have an optical processor. It's not that easy.
I remember the researcher who created an optical computer that was the size of a room. Why is this? Electrons are small. They bend around corners. They stay put. They move when you want them to. Photons do not bend well around small corners, do not support CMOS-like circuits and generally fail at most tasks of that versatile, tiny doer of great deeds, the electron.
As usual, it's just an optical modulator. Boring old modulator.
(1) In Win2K, shut down Firefox.
. dat
in your favorite ascii editor.
n - service;1 ..." to become ..."
(2) Open \Documents and Settings\YOURUSERNAME\Application Data\Mozilla\Firefox\Profiles\default.XXX\compreg
(3) Search for 'idn' in Note/Wordpad. Comment out with a '#' the line that says
"{NUMBERSLETTERSDASHES},@mozilla.org/network/id
"#{NUMBERSLETTERSDASHES},
(4) Don't worry. Browse happy.
I just returned from the supposedly closed China, and have much to say that contradicts the article. Most of the article plays on the ignorance of Westerners.
The internet cafes were cheap (around $1 for 4-8 hours) and usually a bit dirty. I was blocked from no site except the San Jose Mercury News, and the site was back online in China the next time I checked. It was not the "Great Fire Wall of China" in action. There have got to be more than 100,000 internet cafes. They're on many, many street corners. Some are built with sleeping quarters attached. Maybe there are 100,000 registered internet cafes, but who really registers anything in China?
I am sure many who live in English speaking countries read these things imagine laws might be followed and enfoced like they are in the UK and US. Strict laws require some enforcement. From what I saw and heard and contrary to what I read from the Chinese press, there was hardly a hint of control over the millions of teenagers online.
If Chinese people are kept in the dark, it seems only to be about their own country (about SARS, e.g.). They often know many details about the U.S., including sports scores, movies and news.
For those too lazy to download the RTF of Atlanta Nights, one of the faux sci-fi stories. Here they are.
.
Pain.
Whispering voices.
Pain.
Pain. Pain. Pain.
Need pee--new pain--what are they sticking in me? . .
Sleep.
Pain.
And yes, after I laughed and laughed, in my side I felt pain.
HSS doesn't come cheap. At 4,000 (£2,800) to score a finished CD it's no surprise that some are viewing it with suspicion.
Oh no! America has lost its edge. Not only did a Spanish company produce the software, but there is no dollar figure in the article.
<noun val="point"/>
<prep val="of"/>
<noun val="XML"/>
<verb val="is"/>
<contraction val="it's"/>
<adjective val="easy"/>
<infinitive val="to"/>
<verb val="read"/>
<period val="."/>
Thank you to the reviewer for posting such a stale old story. I haven't had such a good laugh on /. for quite a while.
A few more news items:
Elephants are comming over the Alps. Head for the hills!
Man discovers fire.
Leave Troy now!
H.J. Round (1907) is credited, somewhat correctly with the invention of the blue-green LED. See this
I think real blue LEDs came about in the '60s.
Nakamura's great contribution was to use lateral overgrowth to produce the first practical blue laser. In engineering, people get more credit for practicality than first display of a principle.
But the introduction of solid-state silicon-based lasers is nothing short of revolutionary.
It's not a silicon-based laser, but rather a silicon-based optical modulator. Thus, it is not revolutionary.
These are not the lasers we're looking for. Move on.
I read the Nature article on which the link was based, and the linked article is dead wrong. It is not an all-silicon laser, since it requires another laser to run. Worse than that, it appears to be close to a silicon optical switch, which can be modulated at a high rate.
The Nature article called it a "High Speed Silicon Optical Modulator," and "optical modulator" != "laser"
If these guys had produced an electically-driven continuous-wave silicon laser, they should get a Nobel Prize. Instead it looks like a rehashing of well-known principles to sound better in a slick-looking, flawed article.