Photochemical effect of laser

[photonicsourcing]

Can anyone explain me about this effect? I found the laser can generate chemical reactions in tissues. What are the long-term consequences?

 

[LSRFAQ]

Can anyone explain me about this effect? I found the laser can generate chemical reactions in tissues. What are the long-term consequences?

Which wavelengths, which tissues? This is a very broad question.

Steve

 

[photonicsourcing]

Yes, I asked a broad question. The idea is that i'am going to have some experimental hours in college and i was wondering if after an accident I could get hurt. I guess that in the lab are not very powerful devices used. Someone told me that there is even the risk of cancer if for example the skin is in contact with laser beam

 

[HIMNL9]

high powers in UV and near-UV bands causes burns more easily than lower wavelenghts ..... and prolongued expositions to highest wavelenghts, like far UV, can cause skin cancer (same as sunrays, if too big part of the UV become passing the ozone layer) .....

For different effects, you need to be more precise in the question, sorry .....

 

[Benm]

You must narrow down your question to get a good answer, i think.

In general, caution should be advised when dealing with near-uv lasers like bu rays. While 400 nm is often cited as the limit between visible light and dangerous UV, the distinction isnt that hard in the real world. There is no good reason to assume that prolongued exposure to 405 nm poses little health risk.

On the other hand there is no reason to assume that briefly shining a blu ray laser at your skin elevates the risks of skin cancer either, but i think its best to err on the safe side with that. Don't take any risks unless you either accept the danger or its proven absent!

 

[Flaminpyro]

Are there any medical lasers that use 400nm ? I could be wrong but I think they use IR in medical devices so you might think twice about using a 405nm laser on your skin...

 

[Benm]

Medical devices are used on various wavelengths, but not around 400 nm.

I'm sure they would be if they had practical application, but it seems there arent any for now. Most lasers in medical use are there for mechanical application (ie cutting tissue) and IR works well there.

There is however some application for visible wavelengths too - but that involves lasers 500 nm and upwards usually.

 

[Bluefan]

Excimer lasers at 193nm are used in eye surgery but not to cut tissue, but to remove it. But 193nm is already deep in the UV.

 

[Benm]

That's plain ablation indeed - as you would expect from a deep UV source.

Visible lasers are also used to treat numerous issues - like certain skin problems or hair removal, but those dont operate around the 400 nm mark either, since that would ineffective.

 

[davidgdg]

(Apologies for mild necro)
I think you are referring to long term damage done by blue light from 400 up to maybe 480. I did a posting on this a while back before the 445s emerged. There is no consensus as to the existence or extent of the risk. It is not specifically a laser issue. But basically, you should avoid staring at a blue or blu ray spot for too long and certainly if using a 445 for burning, goggles should be worn.