Photon Emission: Difference between revisions

Latest revision as of 12:14, 7 April 2017

Spontaneous Photon Emission

Page in progress by kylerasmussen44

Revised by Sunny Chen (schen474) 2017

Photon Emission is a process that occurs when an atom or other quantum system goes down an energy level, and releases a photon. This process is often incited by the absorption of a particle whose energy causes an atom to increase its energy level; in this case, spontaneous photon emission would move the atom to a lower energy level, closer to its initial state (i.e., ground state). Photon emission is responsible for most of the light that we see, being given numerous names such as luminescence, fluorescence, and phosphorescence.

The Main Idea

Spontaneous photon emission is fundamentally a quantum process, with its principles first being discovered by Paul Dirac. This phenomenon can best be described by using the theory of zero-point energy, or ground state energy. As an electron or similar particle gains enough energy to move out to a higher energy orbit then back to its ground state, it has to lose energy to fall back down into the lower orbitals. The only way it can do this is by releasing a photon. As the particle experiences an electronic transition from the excited state to the ground state, energy is released in the form a photon.

A Mathematical Model

For a simple mathematical model, a light source is in an excited, higher energy state with energy [math]\displaystyle{ E_2 }[/math], and it decays into a lower energy level with energy [math]\displaystyle{ E_1 }[/math]. This change in energy is expressed in the form of an emitted photon with the energy being calculated as the angular frequency [math]\displaystyle{ \omega }[/math] times the reduced Planck constant [math]\displaystyle{ \hbar = {{h}\over{2\pi}} = 1.054\ 571\ 800(13)\times 10^{-34}\text{ J⋅s} = 6.582\ 119\ 514(40)\times 10^{-16}\text{ eV⋅s} . }[/math]

Examples

A visual example of spontaneous photon emission is shown below.

Connectedness

How is this topic connected to something that you are interested in?

This topic is interesting because it is how most of the light that we see is emitted. This is the basis of our vision and our world. Without this principle, we would not understand how electromagnetic radiation affects our bodies.

How is it connected to your major?

This is not connected to my major of Industrial Engineering, but I found this topic extremely interesting, and I wanted to explore the principle.

Is there an interesting industrial application?

There are many industrial applications which connect photon emission. This principle is used in everything that emits electromagnetic radiation, including lasers, glow in the dark paint, and anything that works by exciting particles in order to produce light.

History

Although photon emission has always existed, we have never understood how it works. This is one topic that we can safely say that we discovered, not invented. The principle was first explained by Paul Dirac in his quantum theory of radiation. In 1963, the Janes-Cummings model was developed. This model describes the system of a two-level atom interacting inside a quantized optical cavity. This theory is exclusive in the fact that in earlier studies of the quantum theory of radiation, only the atom was quantized, and the field was treated as a definite function of time. This change had a profound effect on quantum electrodynamics, allowing the studies of cavity quantum electrodynamics.

References

Jaynes, E. T.; Cummings, F. W. (1963). "Comparison of quantum and semiclassical radiation theories with application to the beam maser". Proceedings of the IEEE. 51 (1). doi:[1]
Milonni, Peter W. (1984). "Why spontaneous emission?" (PDF). Am. J. Phys. 52 (4): 340. Bibcode:1984AmJPh..52..340M. doi:[2]
3. F. van Driel, G. Allan, C. Delerue, P. Lodahl,W. L. Vos and D. Vanmaekelbergh, Frequency-dependent spontaneous emission rate from CdSe and CdTe nanocrystals: Influence of dark states, Physical Review Letters, 95, 236804 (2005). doi:[3]

@@ Line 1: / Line 1: @@
 Spontaneous Photon Emission
 Page in progress by kylerasmussen44
-Short Description of Topic
+Revised by Sunny Chen (schen474) 2017
-Photon Emission is a process that occurs when an atom or other quantum system goes down an energy level, and releases a photon. This process is often incited by the absorption of a particle whose energy causes an atom to increase its energy level; in this case, spontaneous photon emission would move the atom to a lower energy level, closer to its initial state.
+Photon Emission is a process that occurs when an atom or other quantum system goes down an energy level, and releases a photon. This process is often incited by the absorption of a particle whose energy causes an atom to increase its energy level; in this case, spontaneous photon emission would move the atom to a lower energy level, closer to its initial state (i.e., ground state). Photon emission is responsible for most of the light that we see, being given numerous names such as luminescence, fluorescence, and phosphorescence.
+==The Main Idea==
+Spontaneous photon emission is fundamentally a quantum process, with its principles first being discovered by Paul Dirac. This phenomenon can best be described by using the theory of zero-point energy, or ground state energy. As an electron or similar particle gains enough energy to move out to a higher energy orbit then back to its ground state, it has to lose energy to fall back down into the lower orbitals. The only way it can do this is by releasing a photon. As the particle experiences an electronic transition from the excited state to the ground state, energy is released in the form a photon.
+===A Mathematical Model===
+For a simple mathematical model, a light source is in an excited, higher energy state with energy <math>E_2</math>, and it decays into a lower energy level with energy <math>E_1</math>. This change in energy is expressed in the form of an emitted photon with the energy being calculated as the angular frequency <math>\omega</math> times the reduced Planck constant <math>\hbar = {{h}\over{2\pi}} = 1.054\ 571\ 800(13)\times 10^{-34}\text{ J⋅s} = 6.582\ 119\ 514(40)\times 10^{-16}\text{ eV⋅s} .</math>
+==Examples==
-Contents [hide]
+A visual example of spontaneous photon emission is shown below.
-The Main Idea
-Spontaneous pho
-.1 A Mathematical Model
-.2 A Computational Model
-Examples
-.1 Simple
-.2 Middling
-.3 Difficult
-Connectedness
-History
-See also
-.1 Further reading
-.2 External links
-References
-The Main Idea[edit]
-State, in your own words, the main idea for this topic Electric Field of Capacitor
-A Mathematical Model[edit]
+[[File:photon.png]]
-What are the mathematical equations that allow us to model this topic. For example dp⃗ dtsystem=F⃗ net where p is the momentum of the system and F is the net force from the surroundings.
-A Computational Model[edit]
+==Connectedness==
-How do we visualize or predict using this topic. Consider embedding some vpython code here Teach hands-on with GlowScript
+====How is this topic connected to something that you are interested in? ====
+This topic is interesting because it is how most of the light that we see is emitted. This is the basis of our vision and our world. Without this principle, we would not understand how electromagnetic radiation affects our bodies.
+====How is it connected to your major?====
+This is not connected to my major of Industrial Engineering, but I found this topic extremely interesting, and I wanted to explore the principle.
+====Is there an interesting industrial application?====
+There are many industrial applications which connect photon emission. This principle is used in everything that emits electromagnetic radiation, including lasers, glow in the dark paint, and anything that works by exciting particles in order to produce light.
-Examples[edit]
+==History==
-Be sure to show all steps in your solution and include diagrams whenever possible
-Simple[edit]
+Although photon emission has always existed, we have never understood how it works. This is one topic that we can safely say that we discovered, not invented. The principle was first explained by Paul Dirac in his quantum theory of radiation. In 1963, the Janes-Cummings model was developed. This model describes the system of a two-level atom interacting inside a quantized optical cavity. This theory is exclusive in the fact that in earlier studies of the quantum theory of radiation, only the atom was quantized, and the field was treated as a definite function of time. This change had a profound effect on quantum electrodynamics, allowing the studies of cavity quantum electrodynamics.
-Middling[edit]
-Difficult[edit]
-Connectedness[edit]
-How is this topic connected to something that you are interested in?
-How is it connected to your major?
-Is there an interesting industrial application?
-History[edit]
-Put this idea in historical context. Give the reader the Who, What, When, Where, and Why.
-See also[edit]
-Are there related topics or categories in this wiki resource for the curious reader to explore? How does this topic fit into that context?
-Further reading[edit]
+===Further Reading and External links===
-Books, Articles or other print media on this topic
-External links[edit]
+[http://zebu.uoregon.edu/nsf/emit.html University of Oregon interactive demonstration of photon emission and atomic energy levels. ]
-[1]
+==References==
-References[edit]
+#Jaynes, E. T.; Cummings, F. W. (1963). "Comparison of quantum and semiclassical radiation theories with application to the beam maser". Proceedings of the IEEE. 51 (1). doi:[http://ieeexplore.ieee.org/document/1443594/?reload=true]
-This section contains the the references you used while writing this page
+#Milonni, Peter W. (1984). "Why spontaneous emission?" (PDF). Am. J. Phys. 52 (4): 340. Bibcode:1984AmJPh..52..340M. doi:[http://www2.famaf.unc.edu.ar/~vmarconi/moderna1/emision_estimulada_AJP.pdf]
+#3. F. van Driel, G. Allan, C. Delerue, P. Lodahl,W. L. Vos and D. Vanmaekelbergh, Frequency-dependent spontaneous emission rate from CdSe and CdTe nanocrystals: Influence of dark states, Physical Review Letters, 95, 236804 (2005). doi:[http://cops.tnw.utwente.nl/pdf/05/PHYSICAL%20REVIEW%20LETTERS%2095%20236804%20(2005).pdf]
-Category: Which Category did you place this in?
+[[Category:Which Category did you place this in?]]