Help clean a laser lens

[Werty930]

Help I accidentally touched the lens on my new laser and I need a way to clean the lens for free and I can't post any pics because my phone won't let me the laser is green

 

[CheesyWalnut]

you can use a cotton swab dipped in alcohol but I prefer to just some compressed air to blow on it a bit.

 

[steve001]

Many many years ago someone posted instructions and demonstration on the web showing a 5mw red laser leaving burn small marks in wood. There was no modification of the laser itself or the optics of this laser. It was done using two external optics. The first optic was used to expand the beam greatly and the second optic was used to focus the beam into a very tiny spot. A focused 5mw laser can produce millions of watts in a small area. What matters is power density.

 

[crazyspaz]

Many many years ago someone posted instructions and demonstration on the web showing a 5mw red laser leaving burn small marks in wood. There was no modification of the laser itself or the optics of this laser. It was done using two external optics. The first optic was used to expand the beam greatly and the second optic was used to focus the beam into a very tiny spot. A focused 5mw laser can produce millions of watts in a small area. What matters is power density.

First off....wat? What the heck does that have to do with him cleaning a lens? Second, a 5mW laser wont burn anything. Not a true 5mW at least. Millions of watts? Think not...

 

[Phsycodelic]

^ lol. I was searching the forums hoping to find an answer for this same question. All my lasers could use use there lenses cleaned. I was going to use a alchohol wipe that I use for my eye glasses, I figure it wouldn't do any damage to the laser lens but I don't know for sure.

 

[jeffreythe00]

you can use a cotton swab dipped in alcohol but I prefer to just some compressed air to blow on it a bit.

What? How does compressed air clean oil from your finger off a piece of glass?

OP, if your lens is not acrylic. You can use some high purity rubbing alcohol to clean your lens or some high purity acetone. If you don't have either of those you could use lens cleaner like you would use for your glasses.

 

[steve001]

First off....wat? What the heck does that have to do with him cleaning a lens? Second, a 5mW laser wont burn anything. Not a true 5mW at least. Millions of watts? Think not...

Opp's I don't know how I did that. It was supposed to be in the thread
Help focusing my 50mw laser pointer into a burning laser.

For the second part yes it can add up to million or millions of watts either 2.2 million or 22 million if the spot is made small enough. I don't remember clearly because this how to was online more than 14 years ago.

Here's the evidence:

it is important to note that extremely high power densities are achieved at the focal point of a concentrated laser beam. A 10-milliwatt beam focused to a diffraction-limited spot 0.22 micrometers in diameter results in a power density of approximately 30-million watts per square centimeter. Molecular Expressions Microscopy Primer: Specialized Microscopy Techniques - Laser Systems for Optical Microscopy

A 5mw would be 15 millions watts sq. cm. Per sq. millimeter = 150,000 watts

 

[BShanahan14rulz]

5mW is 5mW. But you underestimate what a tiny amount of power can do when it is focused to a tiny spot. Balloon popping? How about bacterium popping!

Also, do want to reiterate Jeffrey's point about not using alcohol on plastic lens, I would guess most are acrylic.

 

[Marco Polo]

If the lens is plastic, cleaning it will probably just scratch it up. If it's a cheap green laser, the lenses are terrible quality and will not tolerate any cleaning at all. At least, not in my experience.

 

[Blarg King]

I would suggest a q-tip and vinegar (perhaps dilute the vinegar in some water). The vinegar should be strong enough to remove oils while not damaging an acrylic lens or damaging any AR coatings if its a glass lens. Make sure the q-tip is really clean and be really gentle so you don't scratch the lens or push it out of place.

I used vinegar on a q-tip to clean the 3 element glass lens on my SF501B without any issues.

 

[CheeseHasLeafs]

Isn't there stuff floating about in vinegar? Will that not get deposited on the lens after cleaning? I too am interested in this, actually. Also, is there any way to tell what a lens is made out of? (If it's sitting in a module).