How many watts to see the beam? How many to burn?

[Cromagnum]

A couple of years ago I bought an overspec (close to 50 mw) violet laser from a member and it worked well for a couple of years until it got dropped (DOH). Looking to replace it with something stronger and was curious what it takes to see a violet beam and what it takes to burn with one. Thanks guys.


Secondly, are any members building any of these in the US in the near future?

 

[mwang]

Well all lasers burn the same at the same power. A 100 mW one is enough for match lighting, and about 500-600 mW should be enough to light a candle. I would get a 100 mW for the beam though.

 

[Cromagnum]

Really only 100mw for match lighting? I thought for sure it would be 300-400mw minimum. 405nm is a really pretty color (when you can see enough of it anyways)

 

[mwang]

Even my 75 mW pen can light a black match. 100 mW is plenty.

 

[cheech226]

yeah, but there's nothing like a 12x putting out 700mW with it's great beam specs.
maybe someday we'll have a watt

 

[Moistenator]

Why not build a 12x as suggested above?

 

[mwang]

If you're building a 12X, just be careful not to overdrive it, the diode dies very easily unlike the M140 445's.

 

[Moistenator]

Don't let it over heat either. Be conservative with the duty cycle.

 

[cheech226]

they are "touchy" diodes. using a soft start driver and limiting current <500mA will keep them happy and proper heat sinking is a must, as with ANY diode

 

[Bionic-Badger]

Well all lasers burn the same at the same power. A 100 mW one is enough for match lighting, and about 500-600 mW should be enough to light a candle. I would get a 100 mW for the beam though.

That is not correct. Different wavelengths are absorbed better by certain materials than others. What is not absorbed gets reflected, and therefore does not contribute to heating. Many organic substances seem to respond better to shorter wavelength lasers than longer, so people often find that their 405nm/445nm lasers burn better, at equal power, than red or IR lasers.

 

[mwang]

That is not correct. Different wavelengths are absorbed better by certain materials than others. What is not absorbed gets reflected, and therefore does not contribute to heating. Many organic substances seem to respond better to shorter wavelength lasers than longer, so people often find that their 405nm/445nm lasers burn better, at equal power, than red or IR lasers.

Well if you want to talk wavelength, that may be true, in most cases, as blue and purple have shorter wavelengths and are more energetic; however, IR will burn better than most visible light lasers, as most objects that we see will absorb IR much more readily than visible light. White paper may reflect all wavelengths of visible, needing approximately 1W of focused laser power to burn, but with IR, it will burn with maybe 500 mW. The same goes for ultraviolet lasers, ones with wavelengths under 300nm.

 

[Th3dArKn3o]

I can barely see the beam on my >500mW 405nm Laser without Fog

 

[cheech226]

if only those m140's were single mode - now that would be a long distance burner.
little 2W tem00 450nm in a handheld anyone?

 

[Cromagnum]

I'm not good with building anything so definitely not going to try my hand at making my own. Any members making (or have one) in the 300mw+ range that they may be selling in the future?

 

[Th3dArKn3o]

if only those m140's were single mode - now that would be a long distance burner.
little 2W tem00 450nm in a handheld anyone?

Not today and not in the near future ...
You have to choose good beam quality and divergence but low power (single mode) or High Power and unbeatable at close up burning but multimode with all the contras !

This only counts for Handhelds though !
You can get 2W+ TEM00 in a 2000$ Labby

 

[Cromagnum]

I keep hearing people refer to this m140 vs 9mm. Do they have a different convergence from one another? I'm pretty noobish when it comes to optics.