Deriving Laser Intensity proportional to N Molecules

  • Context: Graduate 
  • Thread starter Thread starter TheCanadian
  • Start date Start date
  • Tags Tags
    Intensity Laser
Click For Summary

Discussion Overview

The discussion centers around the relationship between the number of molecules in a laser sample and the intensity of the laser output. Participants explore whether the intensity is indeed proportional to the number of molecules, seeking derivations and references to support this claim.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant recalls that the intensity of a laser output is proportional to the number of molecules (N) in the sample, expressing a desire for a derivation or references to confirm this.
  • Another participant requests clarification on the original question, suggesting that there may be confusion regarding the context of the laser application.
  • A participant interprets the question as relating to a lasing sample, proposing that if one mole of CO2 yields a certain output, then two moles would produce twice as many photons, which seems intuitive to them.
  • There is a request for sources that confirm the intuition regarding the proportionality of intensity to the number of molecules.
  • A link to an article is provided, which purportedly contains relevant information and a graph illustrating the increase in intensity with the number of molecules.

Areas of Agreement / Disagreement

Participants express a general intuition that laser intensity is proportional to the number of molecules, but there is no consensus on the derivation or specific references to support this claim. Some participants seek clarification and further context, indicating that the discussion remains somewhat unresolved.

Contextual Notes

There is a lack of detailed derivation or mathematical backing for the claims made, and the discussion relies heavily on intuition and anecdotal reasoning. The assumptions regarding the efficiency and output of the laser based on the number of molecules are not fully explored.

TheCanadian
Messages
361
Reaction score
13
I recall hearing that if you have a sample of N molecules, then the output of a laser consisting of this sample has intensity proportional to N. I've been looking for such a derivation but cannot find one, and am wondering if this is still true. It seems somewhat intuitive but my intuition isn't always right. Any references/explanations would be greatly appreciated!
 
Science news on Phys.org
TheCanadian said:
I recall hearing that if you have a sample of N molecules, then the output of a laser consisting of this sample has intensity proportional to N. I've been looking for such a derivation but cannot find one, and am wondering if this is still true. It seems somewhat intuitive but my intuition isn't always right. Any references/explanations would be greatly appreciated!

Am struggling to understand what you are talking about ... maybe others are as well, hence the lack of responses

can you please expand on what you are referring to
is it a situation of firing a laser at a sample of something and using the reflected / refracted laser light to determine the sample composition ?
or something completely different ... please put you question into context :smile:

Dave
 
davenn said:
Am struggling to understand what you are talking about ... maybe others are as well, hence the lack of responses

can you please expand on what you are referring to
is it a situation of firing a laser at a sample of something and using the reflected / refracted laser light to determine the sample composition ?
or something completely different ... please put you question into context :smile:

Dave
I READ it as a question about a lasing sample. So if a mole of CO2 is in a laser, it has a certain efficiency, and a certain maximum output. And then 2 moles of CO2 would have twice as many photons produced. That certainly seems intuitively to make sense to me as well.
 
votingmachine said:
I READ it as a question about a lasing sample. So if a mole of CO2 is in a laser, it has a certain efficiency, and a certain maximum output. And then 2 moles of CO2 would have twice as many photons produced. That certainly seems intuitively to make sense to me as well.

Exactly. It seems very intuitive and I'm just wondering if there any particular sources confirming this is the case.
 

Similar threads

Graduate The coherence length is much longer than the manufacturer claims
  • · Replies 10 ·
Replies
10
Views
3K
Graduate Fraunhofer diffraction experiment- neural density filters
  • · Replies 7 ·
Replies
7
Views
2K
Graduate E-field of a laser pulse and Intensity
  • · Replies 1 ·
Replies
1
Views
2K
Undergrad Setting up a circuit to drive a Laser Diode
  • · Replies 3 ·
Replies
3
Views
2K
Graduate Intensive vs Extensive Expressions
  • · Replies 3 ·
Replies
3
Views
3K
Graduate Laser induced damage and irradiation time
  • · Replies 5 ·
Replies
5
Views
2K
Laser Beam Diameter which Minimizes Volume?
  • · Replies 1 ·
Replies
1
Views
2K
Graduate Closely-Spaced Modes in Birefringent Single-Mode Fibers?
  • · Replies 5 ·
Replies
5
Views
2K
Graduate Semi-classical argument for stimulated emission?
  • · Replies 1 ·
Replies
1
Views
2K
Graduate Landau's Maximum Mass Limit Derivation in Shapiro & Teukolsky (1983)
  • · Replies 23 ·
Replies
23
Views
3K