Fiber Mall Released 25G DWDM SFP28 20km Optical Module

Optical wavelength division multiplexing technology (WDM), especially dense optical wavelength division multiplexing technology (DWDM), is the most direct and effective solution to increase the capacity of the optical transmission network. With the popularization of 100G and even 400G optical networks, the optoelectronic device solution of C-band single-wavelength 25G DWDM plays a particularly important role in supporting the smooth upgrade of traditional 10G DWDM systems to 25G DWDM systems.

The popularity of high-reliability and low-cost C-band 25G DWDM devices has always restricted the upgrade of long-distance telecom networks based on single-wavelength 25G. Considering the chip resources, device performance, and costs, C-band 25G DWDM devices currently have very few solutions or manufacturers that can supply them in batches. Although the industry provides a relatively low-cost solution that is achieved by overclocking a traditional C-band 10G DWDM EML to 25G, this temporary solution is limited by inherent device performance. There are uncertainties in TOSA performance, yield, and delivery, which greatly limit the large-scale promotion and application of 25G DWDM systems.

In response to this market demand, FiberMall launched a C-band 25G DWDM SFP28 20km optical module recently. TOSA adopts a 25G EML DWDM chip and stabilizes laser wavelength through high-precision TEC. The XMD hermetic packaging ensures high reliability, and the optimization of the signal integrity of each component node ensures the excellent optoelectronic performance of DWDM TOSA, providing 100% support for 25G DWDM applications.

FiberMall’s 25G DWDM EML TOSA devices can transmit up to 20km. The modulation depth of typical 15Km fiber transmission EA is about 1V, and ER is greater than 6dB. The eye diagram margin is greater than 45% before the fiber is connected, and the margin is greater than 15% after the fiber is connected. APD receiver sensitivity is less than -16dBm before the fiber is connected, which is less than -14dBm after the connection, and the TDP is less than 2dB.

the eye Diagram of 25G DWDM EML TOSA

the Eye Diagram of 25G DWDM EML TOSA

This TOSA is applicable to 25G SFP28 LC optical modules, featuring low power consumption, industrial temperature support, high bandwidth, high power, and large eye margin.

25G DWDM SFP28 20km optical transceiver


25G DWDM SFP28 20km optical transceiver


Optical Characteristics

The following optical characteristics are defined over the Recommended Operating Environment unless otherwise specified.

Optical WavelengthλCλc -0.1λc +0.1nm1
Center Wavelength Spacing100GHz
Optical Spectral Width∆λ1nm
Average Optical PowerPAVG05dBm2
Side Mode Suppression RatioSMSR30dB
Optical Extinction RatioER6dB
Transmitter OFF Output PowerPoff-30dBm
Transmitter and Dispersion PenaltyTDP2.7dB
Optical Return Loss ToleranceORLT20dB
Transmitter Eye MaskCompliant with IEEE802.3ae
Center WavelengthλC12701610nm
Receiver SensitivitySen.-14dBm3
Average Receive Power-20-5dBm
Input Saturation Power (overload)Psat-8dBm
LOS AssertLOSA-30dBm
LOS De-assertLOSD-21dBm
LOS HysteresisLOSH0.5dB
Damage ThresholdTHd3dBm


1. λc refers to wavelength selection and corresponds to approximately 0.8 nm.

2. Class 1 Laser Safety per FDA/CDRH and IEC-825-1 regulations.

3. Measured with Light source 77~1563.86nm, ER=6dB; BER =<10^-12 @PRBS=2^31-1 NRZ.


The promotion and application of 25G DWDM SFP28 will have a large positive impact on the communication network. In telecommunications transmission network applications,  coherent optical transmission technology is required for applications with a transmission distance greater than 80 kilometers at a 25G rate. However, the cost of coherent optical modules is extremely high currently, while the cost of the 25G DWDM SFP28 solution is much lower. In the case of using multi-wavelength DWDM networking, even considering the costs of fiber amplifiers and dispersion compensation modules, the 25G DWDM SFP28 plus optical amplifier plus dispersion compensation solution still has a huge cost advantage. In addition, in 5G construction, 25G DWDM SFP28 also provides a more efficient low-cost mid-fronthaul solution than LWDM and MWDM.

Since this year, FiberMall has increased investment in automation construction to ensure product quality and improve product performance consistency. An internal automation team has been set up to transform outsourced equipment according to its own proprietary technology. Related automation equipment is developed to promote the automation process construction of each product line. FiberMall’s 25G DWDM SFP28 is compatible with the 10G DWDM SFP+ production process, which has achieved automated production of the entire process. The automated route combined with a simple optical module production structure and efficient process flow ensures a very high pass-through rate and yield of the optical module and effectively reduces the cost of the optical module.

The mass production of FiberMall’s 25G DWDM SFP28 20km optical module provides a high-performance, highly reliable, and predictable low-cost optical module solution for the 5G fronthaul applications and the industry to smoothly upgrade from 10G DWDM optical transmission system to 25G.

FiberMall’s products cover various rates from 100M to 400G and various packaged optical transceivers and cables, including low-speed 100M, 1.25G/2.5G SFP, GPON OLT/ONU, 10G XFP, SFP+, and high-speed 10G optical modules such as XGSPON OLT/ ONU. We also offer 40G QSFP+, 100G QSFP28, CFP, 400G QSFP-DD, and other industry-leading optical modules and direct-connect cable products. We can provide CWDM, DWDM passive wavelength division solutions, OTN transmission solutions, FTTX solutions, 5G fronthaul solutions, and DCI transmission solutions for global customers.

In recent years, FiberMall has successively developed 25G MWDM QSFP28 for 5G applications and 100G DWDM QSFP28 80km optical modules for DIC transmission applications. The air-tight TOSA used in the 25G DWDM SFP28 20km optical module enables FiberMall to provide customers with a full set of mass-produced high-performance and high-reliability optoelectronic integrated device solutions at rates from 10G to 400G, further consolidating FiberMall’s dominant position in the optical communication industrial chain.

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