Renesas Electronics Corporation has made available the new series of semiconductor laser diodes, the “NX6375AA Series”.
The newly developed direct modulation distributed feedback laser diodes (DFB LDs,) support 25 Gbps × four wavelengths operation as the light sources in 100 Gbps optical transceivers that are used for communication between servers and routers installed in data centers.
The NX6375AA Series enables system developers to develop high-speed optical transceivers and optical modules that are highly reliable even in high-temperature environments, and the new series can be implemented in the servers and routers used in data centers. The NX6375AA Series is available for mass production.
Recently, due to the popularity of cloud computing for the IoT era, the scale and processing capacity of data centers that are connected to the internet and handle large amounts of data are expected to increase at an annual rate of 59 percent . In the optical transceivers used for communication between the servers and routers in the data centers in that environment, there is now demand for increased speeds in the transmission rates, and it is expected that the 100 Gbps systems, which will replace the current mainstream 40 Gbps systems, will see an annual growth rate of 75 percent.
However, there is concern that the increasing system heat generation, which is proportional to the communication speed, could make the system operating state become unstable, therefore, achievement of both stable operations in high-temperature environments and higher communications speeds has become a major issue for optical transceivers.
Renesas launched its semiconductor LDs for this area starting in 2004, when the communications rate was 10 Gbps. The new NX6375AA LD Series support 100 Gbps systems, which are expected to become the mainstream in communications systems in the future and by resolving the issues in this area as described above, will contribute to higher speeds and increased reliability in user optical transceiver devices.
Key features of the new NX6375AA Series:
Industry’s first to achieve stable operation at up to 28 Gbps per wavelength over an operating temperature range of Tc = -5°C to 85°C
The LDs not only support 100 Gbps with four wavelengths, but also are capable of supporting up to 112 Gbps systems. Furthermore, the LDs use Renesas’ unique embedded structure and adopt aluminum gallium indium arsenic (AlGaInAs) as their materials. Therefore, the LDs can achieve a maximum 28 Gbps transmission rate over the wide operating temperature range of Tc = -5°C to 85°C by optimizing the DFB structure.
The four wavelengths in the LD series are 1271, 1291, 1311, and 1331 nanometer (nm), which support the wavelength spacing of the CWDM Renesas’ unique technology.
Assuring high reliability of an MTTF of 100,000 hours
To enable these LDs to be used safely in data center environments, Renesas used narrow width selection growth technology for the wafer crystal growth, controlled crystal defects in the active layer, and formed a protective aluminum oxide layer (Renesas’ unique technology). Since aluminum oxidation can be controlled during fabrication, these laser diodes achieve the industry leading mean time to failure (MTTF) level of 100,000 hours, assuring a high reliability.
Renesas intends to actively expand its LD lineup for 100 Gbps high-speed communication applications. Renesas is also working on expanding the operating temperature range of its LDs in the low temperature direction, which is required for applications such as communications base stations. Furthermore, Renesas can provide solution proposals with even higher levels of added value by combining these LDs with Renesas high-speed optical reception devices and Renesas microcontrollers (MCUs).