Welcome to Laser Pointer Forums - discuss green laser pointers, blue laser pointers, and all types of lasers



Focused laser makes strange effect on my safety glasses

leo.b

New member
Joined
Apr 3, 2020
Messages
8
Points
3
Hi,

I had focused my red laser module ( 60-70mw) to the maximum, to get the smallest dot, for some “burning“. I put then my blue eagle pair glasses on and burnt some black tape. I noticed, when i reached the smallest dot, it started to get like a withe dot, and no more red for this moment.

did anyone know, if this is bad for the eyes, or if maybe the safety glasses can not filter such a little dot and then it gets this bright white dot?

i noticed similar on a 405nm laser with my orange OD6 eagle pair safety glasses.

greetings from switzerland ✌🏻
 



Petersoft

Member
Joined
Feb 16, 2020
Messages
33
Points
8
Hi,

I had focused my red laser module ( 60-70mw) to the maximum, to get the smallest dot, for some “burning“. I put then my blue eagle pair glasses on and burnt some black tape. I noticed, when i reached the smallest dot, it started to get like a withe dot, and no more red for this moment.

did anyone know, if this is bad for the eyes, or if maybe the safety glasses can not filter such a little dot and then it gets this bright white dot?

i noticed similar on a 405nm laser with my orange OD6 eagle pair safety glasses.

greetings from switzerland ✌🏻
When the laser beam is focused to infinity and burns something, very often plasma is generated on the surface of the material being burned, hence white light appears. Protective glasses cannot block white light because it would mean that they block any color because white light is a mixture of all colors. However, when it comes to eye safety, looking at such a white spot should not damage your eyesight. I hope I helped. :)
 
  • Like
Reactions: GSS

leo.b

New member
Joined
Apr 3, 2020
Messages
8
Points
3
When the laser beam is focused to infinity and burns something, very often plasma is generated on the surface of the material being burned, hence white light appears. Protective glasses cannot block white light because it would mean that they block any color because white light is a mixture of all colors. However, when it comes to eye safety, looking at such a white spot should not damage your eyesight. I hope I helped. :)

okay wow.... 😄

thank you for your answer ✌🏻
 

paul1598419

Well-known member
Joined
Sep 20, 2013
Messages
17,455
Points
113
Doubt you would see much plasma from a 70 mW laser focused down as far as it would go to burn with. I have focused down much higher powered lasers to burn with and never saw plasma even without goggles. You might just be seeing the diffused spot through your goggles. If you aren't burning reflective materials, unlikely, you shouldn't need goggles at all as the laser is only focused to a point an inch or two from the material being burned and even if reflected would not be colimated at your eyes. This is quite a different situation than a laser focused to "infinity". At this focus, the beam could be reflected off a surface like glass and remain colimated to your eyes.
 
Last edited:

Cyparagon

Well-known member
Joined
Sep 12, 2007
Messages
9,798
Points
113
"plasma" is one of those words thrown around a lot. In some scenarios it means partially ionized gas, and in others it refers only to fully ionized gas. A flame often has some partially ionized gas, so if you're being pedantic, you could call a candle flame plasma.

The white you're seeing is from incandescence.
 

FuzzyPancake

Member
Joined
Mar 4, 2020
Messages
46
Points
18
"plasma" is one of those words thrown around a lot. In some scenarios it means partially ionized gas, and in others it refers only to fully ionized gas. A flame often has some partially ionized gas, so if you're being pedantic, you could call a candle flame plasma.

The white you're seeing is from incandescence.
Do we think there is any possibility of vision damage from staring at this incandescence from, say, a piece of wood being burned by a focused 1.6W 445nm laser (with adequate laser protection) from six inches away? I've noticed this same phenomenon while wearing OD5 goggles with my 1.6W and assumed this generated light was pretty harmless, but I make sure I stay two feet or so from it to be safe.
 

Cyparagon

Well-known member
Joined
Sep 12, 2007
Messages
9,798
Points
113
Not really. The maximum intensity is limited by the melting point or boiling point of the combustion products. The same is true of any incandescent lamp.
 

hakzaw1

Well-known member
Joined
Apr 2, 2009
Messages
10,205
Points
113
Quick tips on how to select the proper protective eyewear
  • Know your laser’s wavelength.
  • Determine the protection level needed based on your laser’s output parameters, or look for the recommended Optical Density (OD). This can be found in your laser manual.
  • Select a filter whose specifications match the above information. Choose one that offers the highest visibility (VLT).
  • Find a frame that’s right for you. For prescription options, choose a fit-over frame or click here for more information on prescription laser safety lenses.
  • ^^^ google search,
If you read the threads the 'experts' never refer to eye ware using the COLOR of the lens... Blue Laser goggles are NOT blue while Blue Glasses are often used for red lasers-- AND the most spendy bloc all or nearly all visisble lasers and IIRC they are Grey in 'color'

Just do this-- READ what is printed on your eyeware frames...
there should be two 3 digit numbers like 400- 540---those are wavelengths,
then see a OD number - say 5.0 --these would give some protection from 'Green' and 'Blue' lasers-- regardless of the color of the lens.
my Eagles have nothing printed on frames--just: Eagle Pair CC..?
I use them for red lasers and blue lasers--the lens is dark green....hmm

hak
 




Top