Chip for fast pulses

Maybe

Some CMOS parts make 200 ps edges.

Eclips Lite (EL series) and GigaComm (NB7) are fast ECL logic families. Some Giga parts have 35 ps rise and fall, but tiny swings.

There are some interesting laser drivers around, like the SY88022.

There were some really fast Russian parts but I don't know if they still can be had.

Step-recovery diodes and NLTLs (shock lines) make the fastest all-electrical pulses. Laser stuff gets truly fast, fs and as optical pulses.

Interesting. I'm seeing a *lot* of adverts on Ebay currently for "optical TDRs" which must be challenging to produce (to my VHF mindset anyway). So yeah, I'm perfectly certain SRDs would be more than adequate for anything I wanted to do. NLTLs I'm not familiar with so gonna have to look 'em up.

Optical TDRs have VHF bandwidths. It's the /modulation/ they show. They certainly don't have the 600-odd THz bandwidth you seem to imply.

Jeroen Belleman not

Ah - well that would explain a great deal! Thanks.

Some cheap gain-switched laser diodes can make picosecond pulses with simple, slow drivers. One can launch that down a fiber and use a fast photodiode to look for reflections.

Or just pulse a ld for a few ns, to get meter-range resolution.

The most used IC in that application is the MAX3949 [1] but I also saw the SY88022AL [2].

We use the SY part to generate fiducial pulses in a biggish laser modulator. What's cool is that it has a diff ecl/cml input, diff high current outputs, and you can smoothly adjust the output amplitude from zero to max. And max is pretty big.

And they only cost about $7.