I think that you should be able to take the signal right out of the backbiased diode and run it straight into a microwave mixer w/ a fixed 7 GHz LO and frequency discrimitate the IF output from the mixer to generate a control signal for your LASER.
In theory, if your LASERS were very, very, very good, you might be able to achieve phase lock, but I'd not hold my breath. A discriminator can give you frequency lock. YMMV, -John ================= > On Mon, 1 Apr 2013 14:24:58 +0100 > Wolfgang <[email protected]> wrote: > >> On Monday 01 April 2013, Attila Kinali wrote: >> >> [APD...] >> > >> > I think the gain modulated approach to downconvert the signal should >> work. >> > >> Anyway, each of these down-mixing approaches needs to resolve the >> mirror frequency problem. I.e. if you modulate your receiver with >> 7.1 GHz (or use an EOM to do that optically) and detect at 100 MHz, >> you do not know whether the input signal has an offset of 7.2 GHz >> or 7.0 GHz. >> So you might be locking on the wrong one. > > If i'm not mistaken, this shouldn't be a problem > I'm not demodulating the laser, but using a PLL to fix the difference > frequency. Being on the wrong side would invert the sign on the loop > gain, thus the mirror freuquency would be an unstable point. > > Attila Kinali > > -- > The people on 4chan are like brilliant psychologists > who also happen to be insane and gross. > -- unknown > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
