Look into EDFA amplifier systems. They work over a range of bands and are pretty affordable.

They can carry regular 1310nm as well as C-Band. Although if you are carrying C-band you may have to compensate for chromatic dispersion.

Happy to help, I love this stuff!

On Fri, Sep 24, 2021 at 4:39 PM Randy Carpenter <rcarpen@network1.net> wrote:

How is everyone accomplishing 100GbE at farther than 40km distances?

Juniper is saying it can't be done with anything they offer, except for a single CFP-based line card that is EOL.

There are QSFP "ZR" modules from third parties, but I am hesitant to try those without there being an equivalent official part.

The application is an ISP upgrading from Nx10G, where one of their fiber paths is ~35km and the other is ~60km.

thanks,
-Randy