J
Joerg
John said:Advanced control algorithms presuppose that the actual "plant" state
can be accurately measured as the thing to feed back against. It's not
obvious to me that you have an accurate realtime wavelength sensor,
either in the production system or even for initial laser/tec
characterization.
There is a really nice optical spectrum analyzer. Sweet. Works like a
champ. Long story short I got the PID thing going today but it's too
slow for my taste, around 3secs per 100pm for TEC control. The
difficulty in this case is that we must scan until we hit a resonance
and then lock. The location of that resonance isn't known a priori.
Pretty much like an etalon where it's all flat and then there is a
valley of just a few pm into which we have to lock. Ok, we also have the
diode current as a lasso but it still feels like barreling down Lombard
Street in a tanker truck and suddenly having to stop on a dime.
Hell of a storm here last night. There's debris all over, lots of palm
tree bits on Dolores Street, and some traffic lights are out. Jim and
the boys should get it next.
Same here east of Sacramento. It even tore the pool sweep
quick-disconnect off which never happened before. Now a cold front rolls
in. But when I came home from the client my wife had already stoked the
wood stove really good. Nice! Time for an Irish coffee.