In the field of optical communications, the demand for high-speed connections continues to surge , and 100G optical modules have become the core of building intelligent networks. Faced with a variety of models such as SR4/LR4/ER4, how should engineers choose? This article uses 5 major classification dimensions + practical selection solutions to help you overcome the selection difficulties!

1. Packaging Determines Performance Boundaries: 100G QSFP28 VS CFP

▶ QSFP28 - Preferred for high-density deployment.
Small size (compatible with QSFP+), hot-swappable; low power consumption, suitable for high-density deployment; supports 4×25G NRZ or 1×100G bit PAM4 modulation.
Typical applications : data center interconnect, 100G Ethernet, 5G forward/intermediate transmission.

▶ CFP/CFP2/CFP4 - Long-distance transmission. The original
early 100G standard, with a large size (CFP4 is relatively compact); high power consumption, gradually replaced by QSFP28; supports longer distance transmission ( such as CFP2-ER4 up to 40km ).
Typical applications : early metropolitan area network, backbone network.

2. Distance determines the technical route

3. Hidden secrets in modulation technology

NRZ traditionally uses
A single channel at 25G rate, and 4 channels in parallel can achieve 100G; The technology is mature and the cost is low; The spectrum efficiency is low.
Typical module : 100G QSFP28 SR4/LR4.

PAM4 innovates
the 100G rate of a single optical port channel, achieving 100G on a single channel ; the spectrum efficiency is doubled; it has high requirements on the linearity of optical devices and requires DSP compensation.
Typical modules : 100G QSFP28 DR1/FR1/LR1/ER1/ZR1 (future 400G compatible).

4. Fiber Mode Selection Rules

The multimode solution (MMF)
uses multimode optical fiber (OM3/OM4) with a core diameter of 50/62.5μm; short-distance transmission (≤150 meters) and low cost;
Typical models : 100G SR4, 100G AOC (active optical cable).

The single-mode solution (SMF)
uses single-mode optical fiber (G.652.D) with a core diameter of 9μm; it has long-distance transmission (10km~120km) and is more expensive;
Typical models : 100G LR4, ER4, ZR.

5. Special function type
▶ Tunable optical module (Tunable)

Supports dynamic wavelength adjustment (such as C-band 1530nm~1565nm); simplifies spare parts inventory and flexibly adapts to DWDM networks; the price is 2~3 times that of fixed wavelength modules.

▶ BiDi single-fiber bidirectional module
: single fiber bidirectional transmission; save 50% fiber resources;
Typical model : 100G QSFP28 BIDI LR1

.

ETU-Link 100G BIDI Optical Module

By properly selecting the type of optical module, you can balance performance, cost, and the sustainable development needs of the network architecture.

About ETU-LINK

This is the end of this article! ETU-LINK is committed to providing customers with high-quality, high-performance optical module products, so that customers can better respond to the ever-changing market demands.