Need high power w/ spot diameter of <= 5 microns, close focus OK

grainde said:

Sorry, but what colour is the silicone you are trying to cut. If on the graph you showed optical damping is related to absorbance, then the material although "clear" as you put it is coloured and a 532 nm laser might be a better, although more expensive, option. (Your strongest peak on the graph is at ~540 nm!) As 532 is DPSS you'll also have much better beam characteristics and less issues focussing it to a small dot. :beer:

Edit: BTW have you seen this thread? Maybe of interest to you...: http://laserpointerforums.com/f57/diy-laser-cutter-project-58283.html

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graind, thanks I didn't know a laser existed in that wavelength! What kind of Wattage can you get in that color?

Depends whether you want a handheld or lab style. Handhelds go up to around 1 W max. There maybe some exceptions but theyll be stupidly expensive.

BTW the standard affordable wavelengths are 405, 445, 532 (DPSS), 635, 650 - 670, 680?, 780? 808, 980, 1064 (DPSS). There are probably lots more in the IR region...


You can get a 200 - 500 green (532) for a reasonable price:

Lazerer 400 mW 532
Lazerer 500 mW 532

Olike 400 mW 532
Olike 500 mW 532

Id probably look at Lazerer as Olike has received a lot of negative press here lately...

Or even an 800 mW module from Lasever. PM me if you want the price, they told me via PMs, so I assume they dont want it posted publicly? Alternatively you can contact them directly...:Laser Pointer Forums - Discuss Lasers & Laser Pointers - View Profile: LASEVER
They also have a selection of lab lasers upto 5 W! :drool:

Good luck :beer:

to increase absorption of energy

actually a moot point, since earlier you stated that blackening the material is not an option. I like the 532nm idea. these often come in real TEM00 mode, and all you'd have to do is focus it down.

532 is expansive, and is not absorbed by white looking materials, as it is in the middle of visible spectrum. Getting 532 with higher power then 405nm would be really costly, and 405 has the same good beam, if not better, as high power greens are rich on additional modes.

DrSid said:

532 is expansive, and is not absorbed by white looking materials, as it is in the middle of visible spectrum. Getting 532 with higher power then 405nm would be really costly, and 405 has the same good beam, if not better, as high power greens are rich on additional modes.

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True it is expensive in comparison to 405 or 445 diodes, on a dollar per watt basis and you will get a nice beam with a single mode 405. But if your material has a maximum absorbance at 540 nm and a very low absorbance into the UV, youd be better off using green. I couldnt find where he stated the material was white either? He said it was clear, but from the optical damping graph I assume it would also be tinted. You should use the absorbance data to judge whether the laser will be effective. Also if the light is strongly absorbed, you wont need as much power! :beer:

thanks everyone, so far I got a lab bench power supply (mastech clone HY3005D, 0-30V 0-5A) and a 405nm SO6J from DTR's laser shop. I got sidetracked from the project so probably won't post here for a few weeks, but I'll update as things progress.

My next goal is to measure the beam divergence, which I have a few ideas on how to accomplish.
1) place diode on flatbed scanner and pour dry ice fog or party fog on the area, scan an image, use image software to get angle (or NA)
2) mount diode on a stage micrometer aimed at a piece of white paper with a camera on the other side, take pictures of the spot on the paper at several distances
3) cut a hole in a soda bottle, glue glass microscope slide over the hole, mount diode onto glass slide, add water and a few drops of milk to the bottle, take picture from above