You may also find that 100G PAM4 could work. There are some vendors that sell the optic, and an outboard EDFA + DCF pizza box.
Dale Thus spake Tarko Tikan (ta...@lanparty.ee) on Fri, Oct 30, 2020 at 04:25:58PM +0200: > hey, > > > I need to push 100G over 100 km of dark fiber. Since there are no 100G > > pluggable optics with this reach (~25 dB), I have been offered coherent > > transport systems to solve my problem. This is all good and well, except > > total system costs start from high five figures. > > 100G-ZR4 QSFP28 is on the market and works. Just watch out for power > limitations, your typical DC switch might not support it but proper stuff > has no problems providing 6.5W of power. > > -- > tarko