[Laser] Re: Laser diode characteristics.msg

[Alberto di Bene]

G0MRF@aol.com wrote :

>I've noticed that as I slowly increase 
>current up to the lasing threshold the device begins to emit laser light but 
>after about 30 seconds at that current level, the light output decreases and 
>becomes non-coherent again.
>
>Question........Am I seeing an effect which causes the lasing threshold to 
>change as the device warms up?     And is this a normal characteristic?
>[...]
>

Hello David,
   it seems that LF is not your only interest...:-)

I guess you haven't used the feedback pin of the laser diode. Those 
diodes have a photodiobe
inside the same case, which measures the amount of laser light generated 
and produces a feedback
signal which is used to keep the whole thing stable. I had once a 
schematic of its use. If I find it, I will
send it to you directly..

73  Alberto  I2PHD