[Laser] Are these for real ?

[w.fritz at htp-tel.de]

Hello,
DPSS Lasers need to be used in a narrow temperature range, because the  
frequency converting crystals will only operate well in a range around  
25 degrees Celsius. DPSS Lasers in pointer housings with so much power  
are only passive-cooled, so the power output becomes unstable after a  
few seconds. The reason is that the crystals will get hot by the 808nm  
diode output and loose efficiency caused by the high temperature. For  
a sophisticated 95mW Green-Pointer a 1W 808nm Diode is necessary  
(cheap high power pointers only use weaker 808nm diodes which are  
totaly overdriven). But if you blow 1W at a crystal surface smaller  
than a fraction of a millimetre you could imagine how fast the  
temperature will increase.
So if you want a stable DPSS laser with high power, you will need a  
TEC cooled unit. If you only want to play around with a "light saber"  
during the night for short moments, a high power pointer will be enough.
Vy 73
Wilfried