Laser power

[bigmajk]

A little while back I bought a laser from ebay that was shipped from Hong Kong. It was supposed to be <5mW 405nm, however I have no way of measuring the power. Today I got a green <5mW laser from a company with good reputaion in sweden and I noticed some diefference in the intesity. My violet laser seems brighter.

I tried shining on an old thermomemter (non digital) and the violet one initially raises the reading by 1 degree C / sec while the green one does not do very much. Also I tried pointing the laser to the backside of my hand to se if i felt anything. The green one does not feel hot at all, but the violet start stinging pretty much after just a few seconds, to the point of painful.

Since these two are my first lasers I've bough (both were pretty cheap) I am wondering if this is a normal difference between 532 and 405, or if one of the is underspec (or maybe even overspec).

Thank you for your help

 

[lasersbee]

Different wavelengths of of the same power of Lasers will
seem to be at different brightnesses to the human eye due
to the human eye's non linear optical sensitivity.

The only real way to know the power of your laser is
with a Laser Power Meter.....


Jerry

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

 

[bigmajk]

Yes I know about that, but what I'm really asking is wether, in your opinion, the violet is overspecced or if the green is underspecced, judging from the information I provided.

 

[InfinitusEquitas]

405nm is just on the edge of UV, and we can barely see it. 532nm is almost in the middle of the visible spectrum.

There is really no way to say if the green laser is underspec...

The 405nm laser is DEFINITELY overspec though, be careful with it, you could be dealing with as much as 100mW, but probably at least 50mW.

The only accurate way to measure the output of lasers, is to get an LPM... or have them tested by someone with an LPM.

 

[grainde]

Yup as InfinitusEquitas said the 405 is definitely over spec. Heres an idea of what you might get, when ordering from Ebay...http://laserpointerforums.com/f52/cheap-ebay-pointers-some-interesting-lpm-results-73993.html :beer: