Easy and effective aperture cap

[RA_pierce]

There are a lot of you out there with CNI pens... whether it's from NOVA, Dragon, TL, or back when WL actually sold in spec lasers, most of us own one...
I came up with an easy solution to the "My lens is dirty" problem... A lens protector that fits into your laser INTERNALLY (no more unsightly rubber sleeves) and never requires you to remove it just to operate your laser... It is easy to install and the parts you need can be found just about anywhere.
I hope this helps. Enjoy!


http://www.youtube.com/watch?v=30-7hrpYN-Y


Using the plastic lens (without a hole) is also effective at preventing moisture from entering the aperture and clouding up the lens. Like I said, you want to use good quality plastic for best results. Anti-reflective glass would work best (I used to use an IR filter) but plastic is the most easily available.

The advantage to drilling a hole in the plastic lens is to reduce the amount of optical elements in the path of the beam so the beam will stay cleaner and not lose power. By reducing the aperture size from 3mm to 1-1.2mm (just large enough to let the beam pass through), the chance that large dust particles will be able to enter the aperture becomes smaller. Also, with the hole in the aperture cover, you will never have to clean it... because there is no surface for dust to stick to.

ALSO: If your beam exits off center and you want to use method 2 or drill a hole in the plastic aperture cover, you must make sure the hole is aligned with the beam so it is not blocked.

 

[electron]

Another way to get a prefect aperture cap is go to the following site and request free samples, they will give you two free samples of each size, up to ten total.

http://www.stockcap.com/prod_detail.asp?id=99&cat=12

For most CNI oem's, regardless of who branded it, order .531 and get some .500 too while your at it, the sizes run a little different due to the wall thickness; they take about a week to get the samples to you.  These slip on/off really nice and won't mar-up your laser or fall off.

The only issue would be if you need more than 2 of any particular size, then you'd actually have to place an order; which minimal quantity runs between 500 - 1000 pieces at a time.

Cheers

 

[Nordhavn]

Edmund Scientific used to sell tiny lever actuated iris' that could be affixed to the end of a shutter.  Back in the late 80's when 670nm pointers debuted for > $500(!) I made a few based on a mini Mag AA, with a Toshiba TOLD 9205 gain guided diode.  The iris allowed control of the beam size as well as circularization.  (as the beams were oval upon exit with a simple GRIN collimator).  The nice thing was the iris could be effectively closed down doubling as a shutter and a way to protect the surface of the collimator.  I'm not sure the blackened vanes could withstand >300mW class IIIb output of my RPL but the idea has crossed my mind.

This is what they look like:

 

[electron]

Back in the day I used to live right near Edmund Scientific and I remember those.

I can't figure out why you would want to put one of those on an RPL, as it already has a safety shutter on it which also keeps out the dust and I doubt the threads would match-up. The OP was referring to CNI based Lasers and these would be way too big to mount on those lasers.

It would be interesting to see if you do mount one on your RPL and I'd be curious to see a picture of the final product and what you are trying to achieve, I'm not knocking the idea at all, just trying to visualize what you are trying to achieve.

Cheers