Wattage of LASER needed for Raman spectroscopy

  • Context: Optical 
  • Thread starter Thread starter sbrothy
  • Start date Start date
Click For Summary

Discussion Overview

The discussion revolves around the wattage requirements for lasers used in Raman spectroscopy, focusing on the implications of using different power levels, specifically comparing low and high wattage lasers. Participants explore the challenges of detecting Raman scattered photons and the effectiveness of various laser options.

Discussion Character

  • Exploratory, Technical explanation, Debate/contested

Main Points Raised

  • One participant questions the advantages of using low versus high wattage lasers, noting concerns about heat deposition.
  • Another participant emphasizes the need for a strong light source due to the low intensity of Raman scattered photons compared to the exciting photons, suggesting that a more powerful laser may improve detection capabilities.
  • A participant mentions a procedure for filtering noise from the original light source, indicating that the choice of laser may not significantly impact the overall setup.
  • There is a query about whether a 100mW laser would be preferable to a 5mW laser, reflecting uncertainty about the practical implications of wattage in this context.
  • Participants note regulatory issues regarding the purchase of higher wattage lasers for private individuals, with one mentioning they have a registered company that may allow for such purchases.
  • One participant expresses a desire for clarity on whether the effort to obtain a higher wattage laser is justified.

Areas of Agreement / Disagreement

Participants express differing views on the necessity and implications of using higher wattage lasers for Raman spectroscopy, indicating that the discussion remains unresolved with multiple competing perspectives.

Contextual Notes

There are limitations regarding the assumptions about laser performance and detection capabilities, as well as regulatory constraints on laser purchases that may affect participants' decisions.

sbrothy
Gold Member
Messages
1,426
Reaction score
1,288
I'm currently using this document to purchase the parts I need. Being no expert, and looking on the table of the 532nm laser diodes used, it doesn't seem to matter much what wattage the laser should be. Is there any advantages to using either a low wattage or high wattage laser, apart from the heat deposited in the appliance?
 
  • Like
Likes   Reactions: Greg Bernhardt
Physics news on Phys.org
Intensity of Raman scattered photons is several orders of magnitude (wikipedia article suggests 10-6 range) lower than the intensity of the exciting photons, which makes detecting them difficult. My bet is you want as strong light source as possible (or, at least, you need to estimate whether your setup will be capable of detecting anything and filtering the noise from the original source away).
 
  • Like
Likes   Reactions: sbrothy
A procedure for filtering the noise is included in the paper. OTOH, from the paper, it doesn't seem to matter much which laser is actually used. I already have a couple of 650nm lasers. I could try with those....
 
Borek said:
Intensity of Raman scattered photons is several orders of magnitude (wikipedia article suggests 10-6 range) lower than the intensity of the exciting photons, which makes detecting them difficult. My bet is you want as strong light source as possible (or, at least, you need to estimate whether your setup will be capable of detecting anything and filtering the noise from the original source away).

So if I understand correctly 100mW is better than 5mW, right?

EDIT: And yes I realize how basic this question is. I just want to be sure it's worth the trouble, because a private person isn't allowed to buy a 100mW laser here. I have a registered company though....

EDIT2: And these 2 threads of mine should be merged really...
 
Last edited:

Similar threads

  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
Replies
7
Views
3K
  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 6 ·
Replies
6
Views
3K
  • · Replies 5 ·
Replies
5
Views
1K
  • · Replies 9 ·
Replies
9
Views
4K
  • · Replies 14 ·
Replies
14
Views
632
  • · Replies 25 ·
Replies
25
Views
4K
Replies
3
Views
4K