[Laser] Looking and Learning About Solid State Lasers

[w.fritz at htp-tel.de]

Hi Stan,
Diode Pumped Solid State Lasers are converted two times in wavelength.  
First, a 808nm diode laser pumps a special crystal which emits  
infrared laser light at 1064nm. This converted light is  
frequency-doubled by another crystal to 532nm, visible green.
Beside the very slow rise and fall time, DPSS lasers only have a very  
bad efficiency. There are just 10 percent from the optical input power  
at 808nm leaving the last crystal at 532nm. And they need a nearly  
constant environment temperature around 25 degrees celsius. Otherwise,  
the efficiency will decrease fastly near to zero.
If you want to set up a high-speed communication unit via laser, it is  
better to take a diode laser directly, such as a DVD writer laser  
(around 100mW visible red). They are much powerful and fast enough for  
high speed data communication or TV signals.
We made 83,3km with a TV signal with 80mW red.
Best regards
Wilfried, DJ1WF