QSFP 100G DR4 Transceiver

The QSFP 100G DR4 transceiver is a short distance single mode parallel optical module that uses 4 x 25G PAM4 technology to achieve 500 m transmission on single mode fiber through MPO 12 connector. It is a key component in the evolution of data centers from 100G to 400G.

100G DR4 Specifications

Model	QSFP28 100G DR4
Package type	QSFP28
Transmission rate	106.25Gbps (4 x 26.5625GBd PAM4), effective data rate 100G
Modulation scheme	4 x 25G NRZ PAM4 (4-channel parallel)
Electrical interface	CAUI-4（4 x 25.78Gbps NRZ）
Optical interface	MPO 12 APC (only use 8 cores: 4 transmit + 4 receive)
Fiber optic type	Single mode fiber (SMF, G.652)
Transmission distance	500 meters (FEC needs to be enabled)
Working wavelength	1310nm (4 channels with the same wavelength)
Emitter type	4 x DFB/EML or silicon optical scheme
Transmit power	-2.9~+2.9 dBm (per channel)
Reception sensitivity	< -9.1 dBm
Power consumption	<4.5W (typical 3.5-4.5W)
FEC requirements	KP4-FEC needs to be enabled
Operating Temperature	Commercial grade 0℃ to 70℃
Protocol standard	IEEE 802.3cd 100GBASE-DR4, 100G Lambda MSA

Core architecture: 4 x 25G PAM4 parallel

The core of QSFP 100G DR4 is 4-channel parallel singlemode transmission technology:

DR4 Optical Transceiver Core Application

1. 400G to 4 x 100G breakout

The most typical application scenario of 100G DR4 optical transceiver is to work with 400G DR4 to achieve port splitting (Breakout):

Solution value:

One 400G port can serve four independent 100G devices and support phased network upgrades. You can deploy 100G devices first and smoothly upgrade to 400G later, which can save the number of switch ports and rack space.

2. Spine Leaf Interconnection in Data Centers

In newly built data centers, QSFP 100G DR4 can be used for:

• Leaf to Spine interconnection (500 meter coverage range)
• TOR to Leaf uplink
• Scenarios that require a greater distance than SR4 (100 meters)

3. Integrated Platform for Silicon Optical Technology

DR4 transceiver is an important carrier of silicon photonics technology, it have integrated the DR4 architecture into silicon optical chips to achieve:

• High integration: modulator, detector, waveguide single-chip integration
• Low cost: Mass production of semiconductor processes
• Low power consumption: The power consumption of the optical engine is lower than that of the EML solution

Comparison with related 100Gb QSFP modules

100GBASE DR4 vs 100GBASE DR1

Both 100GBASE DR1 and 100GBASE DR4 are branch out forms of 400GBASE DR4 optical transceivers, and all three use single-mode optical fibers. APC connectors must be used to ensure reflection loss. Both are used for short distance interconnection, with a maximum transmission distance of less than 500 meters. However, it is necessary to confirm that the 400G switch port has been configured in “split mode” in order to correctly map the 100G channel.

The core principle of 400G DR4 breakout into 100G signals is to use single labmda 100G optics technology (100G PAM4) to split 4 parallel 100G signals to different downstream devices through fiber optic patch cables. Please find below details of the two breakout schemes:

Connection scheme	1 To 4 Breakout Connection	1 To 1 Direct Connection
Downstream transceivers	100G DR1	100G DR4
Fiber optic patch cable types	MPO-12 to 4xLC duplex patch cords	MPO-12 to MPO-12 patch cords
Number of optical channels	1 channel single wavelength（single lambda optics）	4channel parallel wiring
Interface type	Duplex LC	MPO-12
Fiber count	2 cores（1 transmit, 1 receive）	8 cores（4 transmit, 4 receive）
Application scenarios	Server connection, high-density access (e.g. top of rack (ToR) switch to server connection)	Switch to core and backbone network connection (such as switch stacking or high-density access, mainly through fiber optic distribution boxes or jumpers to change the number of fibers)

100GBASE DR4 vs 100GBASE SR4

In the 100G transceiver module family, the DR4 optical transceiver combines the parallel architecture of SR4 (MPO interface) and the advantages of single-mode fiber, serving as a bridge solution for data centers transitioning from 100m multimode (SR4) to 500m single-mode (FR). It is the standard solution for 500m single-mode parallel interconnection in data centers.   

Item	100G DR4	100G SR4	100G FR	100G LR4
Fiber type	SMF	MMF	SMF	SMF
Transmision distance	500 m	70-100 m	2 km	10 km
Interface type	MPO-12	MPO-12	Duplex LC	Duplex LC
Technical Architecture	4×25G PAM4	4×25G NRZ	1×100G PAM4 (DR1)	4×25G NRZ + WDM
Cost	lower	Lowest	medium	highest
Power consumption	<4.5W	1.8-2.5W	4.0W	3.5W
Applicable scenarios	Internal Data Center	Inside the cabinet	Park interconnection	Metropolitan area interconnection

How to choose?

Scenario requirements	Recommended Solution	Reason
New data center 500 meter interconnection	100G DR4	Parallel architecture compatible with 400G DR4, convenient for future upgrades
Need to split 400G port into 4 X 100G	100G DR4 / DR1	Belonging to the DR ecosystem with 400G DR4, compatible with branches
MPO-12 parallel cabling infrastructure already exists	100G DR4	Directly reuse existing optical fibers
Requires transmission over 2 or 10 kilometers	100G FR / LR4	DR4 distance insufficient
Pursuing the lowest power consumption (interconnection inside the cabinet)	100G SR4	The multi-mode solution has lower power consumption

Conclusion

100G DR4 transceiver is a supporting 100G transceiver module for the 400G DR4 ecosystem – using 4 × 25G PAM4 parallel technology, it achieves 500m transmission on single-mode fiber through MPO 12 interface, and is a key component for the smooth evolution of data centers from 100G to 400G.