Safety glasses + OD factor + IR leakage

pixar

Newly Enlightened
Joined
Apr 28, 2006
Messages
88
Hi,

I have been browsing this forum for some time but just got around to registering in order to post. Currently I have a low power red laser and a 100mw greenie on order. Not exactly sure what make but it looks exactly like many others sold by various companies (wicked, etc) - black body (pen style) with gold body colouring.

I need to buy some protective glasses for 532nm. I know the sporty style sold by wicked lasers have been recommended here and there, but I am worried about the 2.25 OD factor, especially as these are apparently good enough for the 300-400mw lasers sold?

I have seen other places such as biglasers selling glasses with OD's of 6+, which appear to actually sit around OD 7 for 532nm - these are cheaper too. Apparently going lower than 2 OD's for high powers such as 100mw is dangerous. 6 is recommended for 100mw so it seems 4 is an absolute minimum to be fully protected from close reflections. I have no means to check power at 532nm nor IR, so I need to sort that out too.

So, can anyone clarify what they believe is a good OD factor to be safe rather than sorry? I am also a little worried about stray IR leakage as it's often reported the IR filter can move or get damaged - why these filters are not locked solid in their housings seems strange.

Many thanks.
 

Athoul

Enlightened
Joined
Oct 5, 2005
Messages
391
The Barr and Stroud goggles that can be purchased on eBay offer excellent protection to 532nm laser light, far superior to many goggles out there that I have seen. On the down side they have a low visual transmittance, so you won't see much more then a dull orange dot while wearing them. However on the upside they also offer superior protection to 808nm and 1064nm IR radiation.

The best part is they are relatively cheap, usually around $20.
 

pixar

Newly Enlightened
Joined
Apr 28, 2006
Messages
88
Thanks for that - I was worried about buying goggles / glasses off Ebay as I wondered if you could guarantee they did what they were supposed to. Nice to know they stop the dreaded IR.
 

Biglasers

Newly Enlightened
Joined
Mar 28, 2006
Messages
3
When it comes to lasers and eye safety, remember, you only have one pair of eyes. When buying any safety goggles to protect against laser light, make sure that the lenses have a industry standard certification CE(EN207 European standard – L ratings) or a U.S. (ANSI Z – Optical Density Ratings). Some lens come stamped with the certifications printed on the lens or on the frames.



Also, the lens on the safety glass is only effective for a specific laser wavelength. For example, a "blue tinted" lens will not protect against a green 532nm laser. Blue tinted lens are designed to protect against a higher wavelength (red at 650nm). A "amber tinted" lens will not protect against a red 650nm laser. Amber tinted lens are designed for a lower wavelength (532nm).



The higher the OD (optical) rating the better protection against the related wavelength (i.e., longer viewing duration for direct viewing or diffuse /indirect viewing). The lower OD rating, the less viewing time. The green 532nm 5mw to 400mW range will work with a rated lens (eg. a Argon/amber rated for 532nm).



Buy only from reputable dealers or from someone who sells lasers and associated eye protection. Low cost laser glasses may work, but make sure the laser you are using is rated for the OD or L-Rating (CE rating) of the lens. If the goggles you are interested in purchasing don't mention OD or L ratings, be very suspect of the quality of the lens. Ask the vendor for proof of compatibility with the laser you will be using with the glasses. If they can't answer your questions, find someone else.



In case you are interested, check this link for styles that may suit your needs - http://www.biglasers.com/site/1589403/page/776502



 
Top