pangolin safety lense?

[solidude]

15 characters dude

[norty303]

Google for Pangolin safety Scan lens and use the link that goes to the Pangolin site.
there's a full product manual and page there which tells you everything.

you don't have a location filled out in your profile so its difficult currently to advise the best place to buy them.. Usually around $120 I believe

[Galvonaut]

You still have to measure the power density of the beam. The lenses are not a complete solution in themselves. Putting one of these lenses in front of a 40W laser would not stop your eyes from popping! You need to understand more than just the amount the power density is reduced by.

Keith

[swamidog]

here's a start:

http://www.ophiropt.com/blog/laser-m...-a-laser-beam/

you will beed a highly accurate laser power meter.

Hi galvonaut. How can i do that?

My future lasers specs is:
=========================
Output red: >350mw/650nm
Output green: >150mw/532nm
Output blue: >500mw/445nm

beam specifications: Color | Size at aperature | Disvergence
Red 4*2mm <3.5*0.5mrad
Green <3mm <1.5mrad
Blue 4*2mm 2mrad
=========================

How can i measure the power density now? And what to do after that? Thanks!

[norty303]

You have just entered the rabbit hole, and it is deep...

[swamidog]

to complicate things, your red and blue diodes are multimode and not gaussian.

So I get the value of "power density". Then what? is there some value you shouldnt exceed? Or do you need to take that value and do other calculations?

Heres another one i found: http://assets.newport.com/webDocumen...ages/20003.PDF

[Galvonaut]

Hrmm, yeah, it can be pretty complicated. There is a simple method though that is a lot simpler.

If you take a measurement of a stationary beam with a Coherent Lasercheck which has a 7mm aperture (same as average pupil size), as long as it does not exceed 1mW, it is 'safe'. The 1mW per 7mm squared figure has a safety factor of 10.

JStewart runs safety display courses here in the UK - he may contribute here. Where did you say you are, Greece? There may be someone running a safety course near you - very wise when considering audience scanning! I am still re-reading my course manual (2nd time now). It's not something you should do with a little big of knowledge.

Keith

[The_Doctor]

If you take a measurement of a stationary beam with a Coherent Lasercheck which has a 7mm aperture (same as average pupil size), as long as it does not exceed 1mW, it is 'safe'. The 1mW per 7mm squared figure has a safety factor of 10.

Does that mean that it is only safe if the 1mW is spread to no less than 1/10 of that area? After all, if it got any thinner then danger increases, if only to a few cells at a time. Also, 7mm squared ain't the same as 7 square mm, which can bite if you're not looking out for it during calculations, so a tenth of the MPE area spec is presumably 4.9 square mm...

(As well as rabbit holes, look out for strangely wobbly (or weirdly wonky) mirrors trying to eat you. And cats. The cats won't try to eat you but watch out for them anyway.)

[Galvonaut]

Good question - I have no idea and it was something I had questioned myself regarding the single modes I have.

I'm not audience scanning yet and won't until I am confident that my knowledge is sufficient. Despite getting 98% in my exam, I am still not ready. I need to play more and read more - get involved in conversations on audience scanning more

Keith

[Galvonaut]

Sorry, but i think you didnt answer my question about what to do next after youve calculated "power density".

Once you know your power density, you can do several things. If it's safe, nothing more, if not, ensure that the public are not within the NOHD (Nominal Optical Hazard Distance), attenuate the laser (not something I would risk without seriously well designed safety systems) or use a lens to diverge the beam, reducing power density.
You can also move the laser further away. Power density is inversely proportional to the square of the distance from the laser.

You can also use diffraction gratings to reduce power density. You still need to take measurements, particularly the zero order beam(s). These, though, can easily be aimed outside of the audience.

Keith