|
The optical
fiber transmission carried by the various laser diodes such as
the Fabry-Perot laser diode (FPLD), the distributed feedback
laser diode (DFBLD), and the vertical-cavity surface-emitting
laser (VCSEL) starts to study.
Not only the
long-reached (the long-haul backbone and the metropolitan area
networks) but also short-reached (the intra/inter-data center
networks and area link) optical links can be demonstrated via
the combination of the LD and optical fiber.
The demand for
broadband voice and high-quality video data becomes more
important in recent years. The internet-related industry
develops the related high-speed transmission including the cloud
storage network, intra/inter-data center networks, and the fiber-to-the-home
link to integrate the wired and wireless network. From the
abovementioned description, the high data rate in the cloud
storage network or intra/inter-data center networks becomes a
key issue in the future.
The optical
link based on the combination of the multimode (MM) VCSEL and
multimode fiber (MMF) can be regarded as one of the solutions
for data-center applications because the VCSEL exhibits a
low-threshold current, high power conversion efficiency, and low
power consumption. Therefore, the related communication
standards for the VCSEL-MMF link at or beyond 400 Gbit/s start
to be build up. In 2017, IEEE802.3cm standard announced the 400
Gbit/s transmissions over 16 850-nm VCSEL-MMF lanes in
400GBASE-SR16 specification. In 2020, the data rate should be
increased to 50 Gbit/s per channel for the 400GBASE-SR8
specification in IEEE 802.3 cm. In the 400GBASE-SR4.2
specification, the 850-nm and 910-nm VCSELs are utilized to
improve the data rate to 100 Gbit/s per channel. In addition to
IEEE 802.3 Working Group, the Shortwave Wavelength Division
Multiplexed Multi-Source Agreement (SWDM MSA) group also
developed the 40G SWDM4 and 100G SWDM4 standards to demonstrate
the VCSEL-based transmission over different-type MMFs. According
to the 2018 Ethernet Roadmap from Ethernet Alliance, the
Ethernet speed can be achieved to 800 Gbit/s or 1.6 Tbit/s in
2022. In recent years, Finisar and VI-Systems companies further
demonstrate the 100-Gbit/s SWDM4 optical transceiver over 100 m.
Therefore, the high-speed VCSEL becomes the most important light
source of the short-reached data-center networks.
A. Encoding the
VCSEL With the NRZ-OOK Format for Data-Center Applications
B. Encoding the
VCSEL With the PAM-4 Data Format for Upgrading the Data Centers
C. Encoding the
VCSEL With the QAM-OFDM Data Format for Wireless and Mobile
Communications
|
