The dramatically grew in demand for 100G CWDM over the past year. While 100G continues to ramp, the promise of high volume 400G remains omnipresent, albeit a 2019 phenomenon. Customers need existing technologies that ship in production volumes to fill this industry gap. While 100G CWDM is a mature and well-understood technology and will continue to ramp in the coming year, many of the big Cloud Data Center OEMs are turning their sights to 200G, to meet the pressures of enabling faster connections at scale volumes.

200G optical transceivers with their many advantages such as significantly lower latency, power consumption and cost are coming to market now, and are seen by many as a viable, volume-scalable stepping-stone to 400G. The three hot selling 200G optical transceivers for the data center will be introduced in this article.

No. 1

200G QSFP-DD SR8 NRZ

QSFP-DD ports are backwards compatible with QSFP28 which is very important to provide a smooth upgrade path and links with older systems.  The backwards compatibility of the QSFP-DD allows for easy adoption of the new module type and accelerate overall network migration.

Application

It is a high-performance module for short-range multi-lane data communication and interconnects.

The Gigalight 200G QSFP-DD SR8 NRZ optical transceiver is designed for 2×100-Gigabit Ethernet 100GBASE-SR4 applications. The 200G QSFP-DD SR8 optical transceiver is designed to operate over multimode fiber systems using a nominal wavelength of 850nm. This module incorporates Gigalight proven circuit and VCSEL technology to provide reliable long life, high performance, and consistent service. Historically VCSEL-MMF links have been seen by many as the lowest cost short-reach interconnect.

No. 2

200G QSFP-DD PSM8 NRZ

The form-factor for 200G QSFP-DD PSM8 NRZ optical transceivers are similar to 200G QSFP-DD SR8 NRZ.

Application

It is a high-performance module for data communication and interconnects.

The Gigalight 200G QSFP-DD PSM8 NRZ optical transceiver is designed for 2×100-Gigabit Ethernet PSM4 and InfiniBand DDR/EDR applications. The 200G QSFP-DD PSM8 (dual PSM4) module integrates eight data lanes in each direction. Each lane can operate at 25.78Gbps up to 2km/10km over G.652 SMF. It is designed to operate over single-mode fiber systems using a nominal wavelength of 1310nm. The electrical interface uses a 76-contact edge type connector. The optical interface uses a 24-fiber MTP/MPO connector. This module incorporates Gigalight proven circuit and optical technology to provide reliable long life, high performance, and consistent service.   

 No. 3

200G QSFP56 SR4 PAM4

PCB layout and heat dissipation design are crucial challenges for 200G QSFP56 SR4 PAM4. Too many components, smaller QSFP56 package and the larger thermal power consumption which are the main reasons.

200G QSFP56 optical transceiver represents an evolution of the highly popular four-lane QSFP+ form factor is ideally suited for hyperscale data centers and high-performance computing (HPC) environments.

Application

It is compliant with the QSFP MSA and IEEE 802.3cd 200GBASE-SR4 specification.

The Gigalight 200G QSFP56 SR4 PAM4 optical transceiver is designed for  200-Gigabit Ethernet links over multimode fiber. This transceiver is a high-performance module for short-range multi-lane data communication and interconnects. It integrates four data lanes in each direction with 212.5Gbps bandwidth. Each lane can operate at PAM4 53.125Gbps (26.5625GBd) up to 70m using OM3 fiber or 100m using OM4/OM5 fiber. These modules are designed to operate over multimode fiber systems using a nominal wavelength of 850nm. The electrical interface uses a 38-contact edge type connector. The optical interface uses a 12-fiber MTP/MPO connector. This module incorporates Gigalight proven circuit and VCSEL technology to provide reliable long life, high performance, and consistent service. 

Conclusion

200G and even 400G transceivers will start to be commercially adopted starting 2019 and will start taking away the market share from the 100Gbps transceivers. 2019 will be a pivotal year to see how 200G takes hold in the cloud datacenter, and intensifying industry collaboration on 200G standards and interoperability could help position this technology for sustained mainstream adoption while 400G continues to mature.