Moin, I'm currently reading up some stuff on optical PLLs and am stuck with some details i cannot find any data on.
The goal is to make two lasers locked with about 7GHz of offset to eachother. So far, i figured out that PIN photodiodes can go up to several 100MHz transition frequency and avalanche photodiodes are available up to 2GHz. The only photodiodes that go higher are those for the telecom range at 1-1.5um, which is a bit low for my needs. But, i have seen descriptions of such OPLL that work with multi GHz offsets in the 700-800nm range. Now the question is: Do these use special made photodiodes with a very high transition frequency or do they just treat the transition frequency as a 3dB point and amplify the signal after detection? (They do not describe the detection circuit at all, so i guess it must be something readily available) If it's the former, any idea where i could get such photodiodes? If it is the later, how much damping can i assume with PIN or avalanche photodiodes per decade? Thanks in advance! Attila Kinali -- The people on 4chan are like brilliant psychologists who also happen to be insane and gross. -- unknown _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.