FWDM

FWDM (Filtered WDM) modules are the workhorse of access networks where 1310 nm upstream, 1490 nm downstream, and 1550 nm video overlay coexist on one fiber. Unlike fully-blown CWDM/DWDM systems, an FWDM uses a small number of dielectric filters tuned to the exact wavelengths needed — keeping insertion loss minimal. Optiunik supplies 2- and 3-port FWDM modules for 1310 / 1550 nm duplex links, 1310 / 1490 / 1550 nm triplexer applications (PON video overlay), and 1490 / 1550 nm WDM coupling. Packaging includes ABS box, LGX cassette, and bare-pigtail device forms. Typical IL < 0.6 dB on the pass channel, isolation > 40 dB, return loss > 50 dB, and 0–70 °C operating range.