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FrozenGate by Avery
diffuse refraction of green laser light hazardous?
- Thread starter ev23
- Start date
Steve001
Absolutely, part of the issue though is that all of the safety/hazard information I've read is referring to the hazard of the beam itself, or diffuse reflection. Whats happening in this case is refraction, as the beam is passing through a translucent medium and reflecting many times off of the internal surfaces and varying densities of that medium before it emerges in a diffused/scattered. The difficulty in trying to assess the hazard is that most of the equations require the beam divergence as a variable and that is what I'm having a hard time determining, since the beam starts at about 3mm and expands to something like 60mm in about 5 inches of space. At this point there really isn't a 'beam' anymore, more like a haze or diffused cloud so I'm not sure how I would go about taking measurements of it. This looks significantly different than the diffuse reflection which (if I'm correct) should be safe to view from a few feet away with a 30mw 532nm line module. From what I've read about laser safety the focused beam (or specular reflections and even diffused reflections with powerful lasers) is the hazard because it allows an enormous amount of radiation into the eye which further focuses that onto the fovea, which can either heat the retina or cause a photochemical reaction to damage the retina if the blink reflex doesn't react in time or the beam is a wavelength that isn't visible so doesn't trigger the reflex or is so powerful it can cause damage faster than the reflex can respond. If theres anything I'm missing please let me know, or if you have any links to material about diffused laser light or even diffuse reflections that would be great!
Absolutely, part of the issue though is that all of the safety/hazard information I've read is referring to the hazard of the beam itself, or diffuse reflection. Whats happening in this case is refraction, as the beam is passing through a translucent medium and reflecting many times off of the internal surfaces and varying densities of that medium before it emerges in a diffused/scattered. The difficulty in trying to assess the hazard is that most of the equations require the beam divergence as a variable and that is what I'm having a hard time determining, since the beam starts at about 3mm and expands to something like 60mm in about 5 inches of space. At this point there really isn't a 'beam' anymore, more like a haze or diffused cloud so I'm not sure how I would go about taking measurements of it. This looks significantly different than the diffuse reflection which (if I'm correct) should be safe to view from a few feet away with a 30mw 532nm line module. From what I've read about laser safety the focused beam (or specular reflections and even diffused reflections with powerful lasers) is the hazard because it allows an enormous amount of radiation into the eye which further focuses that onto the fovea, which can either heat the retina or cause a photochemical reaction to damage the retina if the blink reflex doesn't react in time or the beam is a wavelength that isn't visible so doesn't trigger the reflex or is so powerful it can cause damage faster than the reflex can respond. If theres anything I'm missing please let me know, or if you have any links to material about diffused laser light or even diffuse reflections that would be great!
GSS
Thanks for the encouragement, yes I hope to be a legit member of the group, I'm just off to a rough start (which, I know, was my own fault) haha. I seem to be getting some good responses today though! Encap's links were really helpful as a thorough overview of laser safety and potential hazards, the chart was especially useful though as it describes the relationship between the different variables and lead me to find the equations, then calculators for the equations which saved me a lot of time! The issue I'm struggling with now though is trying to determine what the beam divergence would be for something like this, since the beam is reflected/refracted so many times within a short distance there is no coherent beam to measure. It starts at 3mm and my guess would be that its something like 60mm within less than a foot, But thats only a guess and I'd like to be more precise if possible, so if you have any idea how I'd go about measuring the divergence in this case please let me know, Thanks!
Thanks for the encouragement, yes I hope to be a legit member of the group, I'm just off to a rough start (which, I know, was my own fault) haha. I seem to be getting some good responses today though! Encap's links were really helpful as a thorough overview of laser safety and potential hazards, the chart was especially useful though as it describes the relationship between the different variables and lead me to find the equations, then calculators for the equations which saved me a lot of time! The issue I'm struggling with now though is trying to determine what the beam divergence would be for something like this, since the beam is reflected/refracted so many times within a short distance there is no coherent beam to measure. It starts at 3mm and my guess would be that its something like 60mm within less than a foot, But thats only a guess and I'd like to be more precise if possible, so if you have any idea how I'd go about measuring the divergence in this case please let me know, Thanks!
You're being blinded more by all the stuff you're reading than what the light emitted from this cube would do. ;-)
In this specific case there is no hazard because this 30mW beam is being scattered in 6 different directions over a siginificantly wider emitting area. Some of the light is also being absorbed and reemited as heat further reducing the emitted visible light. Specular reflect does pose a hazard maybe if this rubber cube's surface is smooth.
P.S. To reply, note the quote and multi-quote tabs. When responding to more than one person in the same thread at the same time use the multi-quote tab.
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Thanks! Thats what I thought and what I was hoping, but I came to get a few more opinions because I am far from an expert when it comes to lasers and I want to be sure theres nothing Im missing.. safety first! Also thanks for the tip for replies