Hi! Where's the mention of safety? On this whole site, I can't find any mention about laser safety... I thought these laser beams could be hazardous if viewed directly or for long periods of time! At adm.uwaterloo.ca I see some information about laser classes. To which class do these laser pointers (5mW?) belong? Is there any real danger? Kids are curious gawkers, you know... they'll check out the source of the beam.
Allan Holm Thomassen - Sat, Jan 27, 01 09:45:19 PM
Hello Charles.
Well... I looked for LASER safty for about 15 sec. and found it. But it is better that we tell people again and again; That they should look at what the text on the LASER say¥s instead of looking for a message in the red light. Who would do that? Kids maby? And this page is for kids therefor the warning maby should be more clear on this homepage. BTW If you have more questions than I am in the holography egroup you can Subscribe by sending a blank mail to: holography-subscribe@yahoogroups.com
(http://www.holoworld.com/holo/quest11.html)
Are LASERs Dangerous?
LASER light is a very "concentrated" type of light and therefore you should NEVER look directly into the beam no matter how low power the laser is. This includes the popular laser pointers currently on the market.
Military LASERs are so powerful that they can knock missles out of the sky. LASERs can provide enough heat to weld metal parts together -- or actually vaporize others.
The LASERs that you will probably come in contact with in your classroom or as an amateur or hobbyist holographer will commonly fall under the category of low-power LASER. You do not need a lot of LASER power to create holograms. Most of the LASERs used for creating holograms fall in the power range of milliwatts, or thousandth of a watt. A good beginning power is 5mW, or 5-thousanths of one watt. These are very safe LASERs to work with, however, as with all LASERs, you still should never look directly into the beam.
Help keep LASERs and holography safe -- practice good experimental proceedures at all times.
212.54.89.211
Vidar - Tue, Jan 30, 01 10:11:41 AM
Hello,
5mW may sound harmless, but the powersupply that drives a HeNe laser of 5mW may very well deliver 5kV at several milliamps - If a kid experiments with the wires between the PSU and Laser while the unit is turned on, that kid will for sure get an experience he or she will never forget! If a young person are encouraged to make holograms, make sure the laser is a solid state laser pointer, not a gas laser!! 195.70.188.204
Mariana - Tue, Jun 19, 01 03:00:41 PM
Hello, I have been workig with a 10mW He-Ne lasser, and just started to feel some irritation in my eyes. I have been very carefull, but the relfection of the expanded beam is strong enough to to irritate the eyes. I recomend using special lenses (very expensive) that filter this wavelenght as I am doing now. Not only the direct beam can burn your cornea, but the heat of the laser in the rest of the eye can damage de muscles and the eye layers. I recomend working with the lights on as much as you can so the pupile is closed while you re setting up the experiment.
take care. M. 132.248.163.119
Colin - Thu, Jun 21, 01 09:12:32 PM
If it feels like you have sand in your eyes you are damaging your eyes. I have gotten hit by the reflection of the unexpanded beam off one of the rods for my optics mounts. Play safe. 64.167.148.203
Lance - Fri, Jun 22, 01 03:07:06 AM
Would it be possible to make a pair of safety glasses? 207.214.183.92
Colin - Fri, Jun 29, 01 07:18:56 AM
In theory you could make a HOE that works as a filter. Or a grating of some sort. Then you would sandwitch the emoltion side in a glass cover and cut it to fit a goggle. It all seems like it would take more time than it is worth. The glasses are about $300 and you could waste a lot of time trying.
If you are bent on trying look at:
Rakuljic, G. A. & Leyva, V. (1993) Volume holographic narrow-band optical filter. Optics Letters, 18, 459-61
Although they used a LiNbO3 recording medium 8mm thick! But you would not need or want such a narrow bandwidth. They reflected a narrow bandwidth (.0125 nm) I am not sure what was transmitted.
If you want to make a colored glass lens you will find the people who know the formulations don't talk about them.
Another option is to vacuum deposit thin films. The chemistry of the films is secret as well and they are very fragile. Nebula filters for astronomy work in this way (they exclude the emission lines from street lights to make the sky apear darker). But they are very expensive and very fragile. 63.193.192.117
Domiinc Moscardelli - Fri, Jan 24, 03 06:32:28 PM
My mom dosn`t trust us!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! 66.227.140.178