Shooting photons 1 per second?

In summary: I think the conversation can be summarized as follows:There is an experiment being set up at a university to shoot photons one per second through slits to prove that light is a wave and that photons can travel through both slits at the same time. However, the Halliday, Resnick, and Walker textbook states that we still do not know a lot about photons. The question is raised about how a machine can shoot out one photon at a time if the photon itself is a mystery. Other participants in the conversation mention different setups in which photon emission can be controlled, such as microspheres, quantum dots, pyramids, and posts. The book "Optical Coherence and Quantum Optics" by Mandel and Wolf is also mentioned as
  • #1
pivoxa15
2,255
1
We might set up an experiment at University shooting photons one per second through slits. I think this experiment was done long ago and proved that light was a wave that was everywhere in that the photon seem to trave through both slits at the same time.

But I read in the Halliday, Resnick and Walker textbook that we still do not know a lot about the photon. So my question is how can a machine shoot out 1 photon at a time?

A photon is not matter so it does not have size or mass. How do we know that the machine is shooting out 1 photon if the photon itself is a mystery?

Thanks
 
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  • #2
pivoxa15 said:
But I read in the Halliday, Resnick and Walker textbook that we still do not know a lot about the photon. So my question is how can a machine shoot out 1 photon at a time?

A photon is not matter so it does not have size or mass. How do we know that the machine is shooting out 1 photon if the photon itself is a mystery?

First of all, the photon is not such a big mystery (well, to some, it is :smile:). It is a relatively well-defined concept in a theory called quantum electrodynamics. So I don't know where H&R get their statement from! Maybe they just wanted to say that at the level of education they work (freshmen?) usually students don't know a lot about photons ?
Hey, this year, the guy who wrote down the entire theoretical framework for optical photons just got the Nobel prize. And he didn't invent the theory, (which was older) he just worked out the framework for optics!

However, to construct a machine that "sends out 1 photon per second" is going to be another piece of cake. I can think of 2 ways: sending out one photon per second ON AVERAGE (meaning, in 1000 seconds, the machine shot out about 1000 photons) is not difficult to do: take a light bulb, and calculate the thickness of the absorber needed. But the photons will arrive randomly.
I could also think of a more pulsed source, which shoots out regularly (every second) an attenuated light pulse, but the pulse will then contain 0, 1 or 2 or 3 photons. No way to let you have exactly ONE photon exactly every second.

cheers,
Patrick.
 
  • #3
There are some setups in which you can control photon emission in order to produce photon on demand. May be, the mode I which this photon goes out is not so well determined. Look up microspheres, quantum dots and photon on demand. Probably you'll find it.

Best Regards

DaTario
 
  • #4
DaTario said:
There are some setups in which you can control photon emission in order to produce photon on demand.

Could you elaborate ? I've indeed vaguely read about having something like an excited atom in a cavity ready to be "triggered" but I'd like to learn more about it.
 
  • #5
An electrically driven single-photon emitter:
http://www.photonics.com/spectra/tech/XQ/ASP/techid.1353/QX/read.htm
http://www.mqc2.it/MQC204/Stevenson.pdf [Broken]

Single photon emitters from pyramidal quantum dots:
http://nccr-qp.epfl.ch/webdav/site/nccr-qp/shared/import/migration/Project02b-3b.pdf

Enhanced single-photon emission from a quantum dot in a micropost microcavity:
http://www.stanford.edu/group/nqp/jv_files/papers/single_photons_APL_May03.pdf

Quantum Dots Emit Single Photons at High Temperatures:
http://oemagazine.com/fromTheMagazine/may04/pdf/eyeontech.pdf [Broken]All the above, Microspheres, Quantum dots, pyramids and posts:
http://www.its.caltech.edu/~mankei/ee150sp03/qdots.ppt [Broken]Regards, Hans.
 
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  • #6
Hans de Vries said:
An electrically driven single-photon emitter:
http://www.photonics.com/spectra/tech/XQ/ASP/techid.1353/QX/read.htm
http://www.mqc2.it/MQC204/Stevenson.pdf [Broken]

Single photon emitters from pyramidal quantum dots:
http://nccr-qp.epfl.ch/webdav/site/nccr-qp/shared/import/migration/Project02b-3b.pdf

Enhanced single-photon emission from a quantum dot in a micropost microcavity:
http://www.stanford.edu/group/nqp/jv_files/papers/single_photons_APL_May03.pdf

Quantum Dots Emit Single Photons at High Temperatures:
http://oemagazine.com/fromTheMagazine/may04/pdf/eyeontech.pdf [Broken]


All the above, Microspheres, Quantum dots, pyramids and posts:
http://www.its.caltech.edu/~mankei/ee150sp03/qdots.ppt [Broken]


Regards, Hans.


Thanks a lot ! I learned something new here.
However, there's one thing that bugs me: how come that the pumping doesn't induce several down-up-down transitions ?
 
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  • #7
vanesch said:
Thanks a lot ! I learned something new here.
However, there's one thing that bugs me: how come that the pumping doesn't induce several down-up-down transitions ?
They talk about single photons from single exitations, that is, single electron hole pairs.


Regards, Hans

BTW: I've just received my copy of "Optical Coherence and Quantum Optics"
from Mandel and Wolf.
https://www.amazon.com/gp/product/0521417112/?tag=pfamazon01-20

Partly because of Glaubers Nobel price (Leonard Mandel is praised in
the Nobel price text for carrying Glaubers work further) and partly
because of our friend nightlight who claimed that the knowledge of
Glaubers work was mandadory for interpreting the results of:
"Observing the quantum behavior of light in an undergraduate laboratory"
http://marcus.whitman.edu/~beckmk/QM/grangier/Thorn_ajp.pdf

The latter fortunately isn't true (it wouldn't be an undergraduate
experiment) The math used for the experiment is rather simple.
 
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  • #8
Hans de Vries said:
They talk about single photons from single exitations, that is, single electron hole pairs.

Yes, I understand that. What I don't understand, is why this single pair, during pumping, doesn't get excited, emits, gets excited again, emits again...
Because the same mechanism that is responsible for the exciting should also be responsible for stimulated emission.

BTW: I've just received my copy of "Optical Coherence and Quantum Optics"
from Mandel and Evans.
https://www.amazon.com/gp/product/0521417112/?tag=pfamazon01-20

It's a great book I have the impression. I read parts of it, but far from everything. I'd like to study it in detail one day...

cheers,
Patrick.
 
  • #9
vanesch said:
It's a great book I have the impression. I read parts of it, but far from everything. I'd like to study it in detail one day...
It's almost 1200 pages :eek:. More a book to pick interesting topics from
instead of working your way through from beginning to end... :smile:


Regards, Hans
 
  • #10
Hans de Vries said:
It's almost 1200 pages :eek:. More a book to pick interesting topics from
instead of working your way through from beginning to end... :smile:
Regards, Hans

Yes, that's what I tried to do too, but it "builds up". You need to read quite a bit from previous chapters to even know what the next chapter is talking about. Happily, the first part is rather classical optics.
 

1. What is the purpose of shooting photons 1 per second?

The purpose of shooting photons 1 per second is to study the properties and behavior of light. By controlling the frequency of photon emissions, scientists can observe how light interacts with different materials and environments.

2. How is shooting photons 1 per second beneficial for scientific research?

Shooting photons 1 per second allows for precise and controlled measurements of light, which is essential for many areas of scientific research such as optics, spectroscopy, and quantum mechanics. It also enables scientists to gather data and make accurate predictions about the behavior of light in various scenarios.

3. How is the rate of 1 photon per second achieved?

The rate of 1 photon per second is achieved by using specialized equipment such as lasers or light sources that emit a single photon at a time. These devices are designed to produce a steady stream of photons at a controlled frequency, allowing for a consistent rate of 1 photon per second.

4. What are some practical applications of shooting photons 1 per second?

Shooting photons 1 per second has many practical applications in fields such as telecommunications, medicine, and environmental science. For example, it is used in fiber optic communication systems, medical imaging techniques like MRI, and studying the effects of light pollution on ecosystems.

5. Are there any limitations to shooting photons 1 per second?

One limitation of shooting photons 1 per second is that it can be a time-consuming process, especially when studying large or complex systems. Additionally, some materials may not react the same way to a single photon compared to a higher frequency of photon emissions, so the results may not be representative of real-world scenarios.

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