Digital Coherent Optics module, hot- pluggable QSFP28 form factor Transmission reach: Up to 80km unamplified (loss limited) Up to 120km amplified (dispersion limited, optionally extendable to 300km) Full C-band tunable, 50GHz or 100GHz grid Case temperature range 0°C to 70°C. Digital Coherent Optics module, hot- pluggable QSFP28 form factor Transmission reach: Up to 80km unamplified (loss limited) Up to 120km amplified (dispersion limited, optionally extendable to 300km) Full C-band tunable, 50GHz or 100GHz grid Case temperature range 0°C to 70°C. Cisco ® QSFP28 100G ZR extends 100GbE coherent links from QSFP28 ports reaching up to 80km over dark fiber and up to 300km over amplified Dense Wave Division Multiplexing (DWDM) links. The Cisco QSFP28 100G ZR module expands the portfolio of digital coherent optics (DCO) modules to connect QSFP28. Built around Coherent Steelerton DSP, the 100G ZR QSFP28-DCO transceiver is fully compliant to the IEEE 802. 3™-2022 100GBASE-ZR standard, ensuring interoperability with other solutions. The Steelerton DSP is the first purpose-built DSP for 100G ZR applications, optimized for the lowest power. QSFP28 (Quad Small Form-Factor Pluggable 28) enables 100G transmission by aggregating four parallel 25G electrical lanes, delivering an optimal balance of bandwidth efficiency, power consumption, and deployment flexibility. Compared with legacy 40G QSFP+ modules, QSFP28 provides 2. 5× higher. A Directly Modulated Laser (DML) uses a diffraction grating to receive inner feedback which is used for stabilising a modulated wave. Direct modulation uses alternating current to power a laser diode. Turning it on activates the laser and this state is interpreted as a logical 1, while turning it. The QSFP28 LR4 is a hot-pluggable, four-channel, and full-duplex optical transceiver module designed for long-distance transmission up to 10 km in the 100G Ethernet network with a working bandwidth of 1295nm to 1310nm. It provides an ideal solution for large-scale data centers for high-demand. When it comes to transmitting data across varying distances, 100G QSFP28 transceivers employ different optical technologies. Shorter reaches typically utilize Vertical Cavity Surface Emitting Lasers (VCSELs), while longer reaches rely on Electro-absorption modulated lasers (EMLs) or Directly.