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Neutral density filter not for high power, but what's the limit?

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makeitnew

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I'm under the impression a neutral density filter could cut beam power down significantly, and at a 1.5 density effectively turn a 100mw laser into a 3 mw laser. But is that ok to do? The glass absorbs the light, but I can't imagine it having an issue with up to 200mw.

Also, am I right on the effect of the filter? 1.5od has a ~3% transmittance. Captain Obvious would say it's 100mw x .03....but who know? i'm still a noob. Would somebody please confirm?
 





lasersbee said:
Hard to swallow that you did a search for Neutral Density Filter...
I just tried it and the 1st hit is this one...:whistle:

http://laserpointerforums.com/f70/extend-lpm-range-filter-74207.html#post1071810


Jerry

You can contact us at any time on our Website: J.BAUER Electronics
Click to expand...

Jerry, that's the second time you've linked me that link. It's not working. why don't you try answering my question instead of trolling me. thanks.


You link doesn't provide me with a confirmation that a nd filter with a 1.5 density would effectively bring down the power of a 100mw laser to ~ 3 mw.

I'm not sure you read my question. I find that hard to swallow.

furthermore by not being friendly, you are giving J.bauer electronics a bad name. I will now never order a laserbee product, and I was saving up for one. so i'll spend it somewhere else now.

I can't apologize enough apparently for not being a electrical engineer with complex knowledge of lasers. Sorry I wanted to take up a new hobby.

should I get down on my knees? What do you want laserbee/Jerry.

I HAVEN'T BEEN ABLE TO ASK 1 QUESTION WITHOUT SOMEBODY TROLLING ME. please stop. i'm doing my best. sorry it's not up to your standards
 
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From what I have read we have different definations of the word trolling.

your questions are not easy ones to answer- can you expalin what you are trying to do??
Some members here read posts and threads and studied the info here for months , even years before asking questions.

This I can tell you- buy your gear from members- if you buy elsewhere and THEN ask for advice you are already at a disavantage. Buy from a vet with good rep. and feedback.
just forget shining your lasers at people alltogether.

maybe lasers are just not right for you.
 
see I would never shine the laser at people in the first place.

I'm trying to find a way to reduce the power of a laser with an optic, but from 100mw down to 3mw or so. I just want to take this unusable 100mw laser and make it a long lasting pointer. I don't want to change the flexdrive If I don't have to. it's a 405nm

thank you very much my good sir.

yes we may have different definitions of trolling. If somebody is flowing me around and posting a link to something loosly related that doesn't answer my question, and then acts all superior about it. This makes me look bad in the eyes of whoever reads the post and therefore I consider it trolling. Kind of in the worst way. he doesn't help, and still complains about me not searchign, when I did search, and have already read his article once before.

furthermore who are you to say lasers are not right for me. You just don't want me around on the forum or probably using lasers. I bet you have all sorts of assumptions about me without knowing anything about me. So get some perspective and don't be rude. Pffft (see reply to pm)
 
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should I assume at this point, nobody will answer my question?

I'm under the impression a neutral density filter could cut beam power down significantly, and at a 1.5 density effectively turn a 100mw laser into a 3 mw laser. But is that ok to do? The glass absorbs the light, but I can't imagine it having an issue with up to 200mw.

Also, am I right on the effect of the filter? 1.5od has a ~3% transmittance. Captain Obvious would say it's 100mw x .03....but who know? i'm still a noob. Would somebody please confirm?
Click to expand...

The only other think I know is that you don't want reflection back into the diode. I already have a fix designed.

I want to do this so I can make it a safe and legal laser. OK?
 
makeitnew said:
Jerry, that's the second time you've linked me that link. It's not working. why don't you try answering my question instead of trolling me. thanks.


You link doesn't provide me with a confirmation that a nd filter with a 1.5 density would effectively bring down the power of a 100mw laser to ~ 3 mw.

I'm not sure you read my question. I find that hard to swallow.

furthermore by not being friendly, you are giving J.bauer electronics a bad name. I will now never order a laserbee product, and I was saving up for one. so i'll spend it somewhere else now.

I can't apologize enough apparently for not being a electrical engineer with complex knowledge of lasers. Sorry I wanted to take up a new hobby.

should I get down on my knees? What do you want laserbee/Jerry.

I HAVEN'T BEEN ABLE TO ASK 1 QUESTION WITHOUT SOMEBODY TROLLING ME. please stop. i'm doing my best. sorry it's not up to your standards
Click to expand...

:wtf:Wow.... What is your F&^$kin problem...:thinking:

The Link works fine....

I got your snooty "Holier than Thou" E-mail yesterday and
had no clue what you were mumbling about but still replied in
a friendly and professional manner.
Then I get another E-Eail from you (Michael Brindle) this morning
stating that I should not bother you...

Are you out of your mind....:thinking:

1) You ask a question and state that YOU have searched but could
not find the answer.

2) I did a 5 second quick search and found a bunch of threads that
talk about ND filters to reduce Laser Power.

3) I even gave you the Search terms to use...

4) I even gave you a link to the 1st search result...

Then you get your little girl panties in a bunch because I didn't
SPOONFEED you the way YOU like and try to Blast my company...

You then open another Thread to Shoot down this Forumout like
a Whiny little girl... GROW UP...

You don't sound like a professional business owner as you tried
to make me believe in your 1st E-Mail to me yesterday...

You sound more like a 13 year old trying to to be an adult but
failing miserably. I can also tell by all the spelling mistakes..

Not to worry I can usually smell a problem customer way in
advance of a sale and I can say with certainty that J.BAUER Electronics
will not sell you any LaserBee Product..


BTW... No LPF Member owes you anything...
When a member responds to any Posts it is because he wants to..
Not because it is required...


Jerry

You can contact us at any time on our Website: J.BAUER Electronics
 
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makeitnew said:
I'm trying to find a way to reduce the power of a laser with an optic, but from 100mw down to 3mw or so. I just want to take this unusable 100mw laser and make it a long lasting pointer. I don't want to change the flexdrive If I don't have to. it's a 405nm
Click to expand...

You know putting an optic in front of the diode wont make it longer lasting... it's still outputting the same amount of power behind the optics lol. Why dont you just buy a purple pointer on ebay... it would probably cost as much as the optics you want to buy.
 
You know.... for the price of a ND filter, you could just buy a cheap-ass laser pointer that is already low power. Even if the ND filter were free, putting an ND filter on the front of a super-low-visibility 405nm laser is going to make it look like a UV counterfeit-money LED-keychain with nearly dead batteries. They're 100mW or so because you can hardly see that wavelength anyway.

So what is the point?

Just buy a different laser with already lower power, and with a wavelength that has higher visibility (like green). Then you're not risking burning out your $25 Flexdrive and your $12 PHR-803T laser diode, and whatever you happened to have spent on that laser you bought for its higher power. It'll also save you the price of an ND filter, the effort of cutting it to size and hot-gluing it to your pointer, and ultimately you'll have a laser that does exactly what you wanted to accomplish, but won't look stupid, and won't be pointless.

This whole exercise is like using a sports car to drive through the crowded streets of central New Delhi, but to be "safe" you're attaching some gears and belts to the wheels so that you can spin the axle at full speed, but not move as fast. Just buy a cheap-ass scooter and be done with it.
 
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