I've got a 10mW laser diode that can transmit at 660 Mbits per second, I've got the laser driver circuit that can do this, I've got a photodiode from Hamamatsu that looks good for this speed (-3 dB ~1 GHz) but I'm struggling to design the photodiode preamplifier.
In my innocence I thought I'd find an op-amp that will do this. I've seen a document posted by Spehro in another answer (question wasn't totally relevant) that gave me some clues and, I came up with a circuit that kind of works (in simulation) based on those ideas but I'm pushing my own limitations now and I don't feel confident so I need advice on the best approach to take. What I have come up with so far is
- Ignore op-amps and
- Use a 9 GHz BJT common-base and an emitter follower.
Am I missing some fundamental approach that could pay better dividends?
Hamamatsu are profoundly silent on the way they coupled photodiodes with a transconductance amp despite the device I'm trying to emulate being discontinued and Hamamatsu say they are moving away from this wavelength photodiodes and lasers. I'm trying to emulate that Hamamatsu device from their now apparently defunct range of 1.3\$\mu\$m products. (G10476)
My question is am I taking a reasonable approach?