QSFP-DD – Optical transceivers
The demand for 400G connectivity is driven by the tremendous requirement for high bandwidth in 5G, loT and cloud data center interconnects.
A series of new IEEE and MSA standards have been put in place to provide several different interface options for both PAM4-based and coherent modulation techniques.
The Smartoptics portfolio includes a first set of PAM4-based transceivers for native 400G as well as 400G to 4x 100G break-out applications. In the latter application, the 400G transceiver is combined with single-lambda 100G transceivers that match the wavelength and optical performance of the 400G transceiver.
The QSFP-DD (DD = Double Density) has become the most popular form-factor for 400G due to its small size as compared to competing solutions in OSFP or CFP2 formats. Digital diagnostics functions are available via the I2C interface, as specified by CMIS (Common Management Interface Specification).
Initially, three options are provided:
- 400G-DR4: for 400G connectivity up to 500m on singlemode ribbon fiber, or for 400 to 4x 100G break-out where the 400G transceiver is combined with four 100G-DR transceivers.
- 400G-FR4: for 400G connectivity up to 2km on singlemode fiber, or for 400 to 4x 100G break-out where the 400G transceiver is combined with four 100G-FR transceivers.
- 400G-LR4: for 400G connectivity up to 10km on singlemode fiber, or for 400 to 4x 100G break-out where the 400G transceiver is combined with four 100G-LR transceivers.