Next-Generation Optical Network Single-Lambda 100G Optics

100G single lambda is a widely used optical specification based on PAM4 signaling. 100G single lambda is commonly used for transmission of 100G data streams over a single wavelength or laser. 100G Lambda MSA governs the development of this specification and it is designed for use in 400G and 100G applications.

The occurrence of 100G single lambda is not uncommon as various optical transceivers such as 100GBASE-SR4, 100GBASE-LR4, 100G-CWDM4 and 100G-PSM4 are equipped with four sets of receivers and transceivers to operate within 25Gb/s parallel lanes. These four optical signals are either optically multiplexed or coupled via parallel fibers to a single fiber for data transmission. This arrangement cannot be implemented without the use of expensive optical components. On the other hand, 100G lambda is a cost-effective solution that results in higher transmission efficiency at lower cost. Transceivers that meet this specification use 100G PAM4 signaling technology for 100G transmission per wavelength – an arrangement that reduces overall cost and optical complexity by reducing the number of optical receivers and transmitters from four to one.

100G Single Lambda Vs. 100G Four Channels

For example, 100GBASE-LR4, 100G-CWDM4 and 100G-PSM4.100GBASE-LR4 is proposed for up to 10km stretched links consisting of 4 multiplexed wavelengths carried by a single fiber. However, closely spaced wavelengths with LAN WDM wavelength spacing cannot be accommodated without expensive hermetic packaging for optimal laser temperature control.

Let us now proceed to the second option, i.e. 100GBASE-CWDM4. This option is better in terms of wavelength spacing, but no connections over 2km are possible with this configuration. Here comes the third option, i.e. 100GBASE-PSM4. This option uses 4 fiber pairs and a wide wavelength for data transmission and thus can resolve the complexity associated with lasers with multiple wavelengths. 100GBASE-PSM4 is a good option, but can only be considered for links up to 500m.

Now let us bring 100G single lambda into the discussion. Three common optical modules included in the 100G single-lambda series are 100GBASE-LR (100G-LR), 100GBASE-FR (100G-FR) and 100GBASE-DR. These optical transceivers are designed to receive electrical signals from a host (in a 4 x 25G configuration) and feature a DSP that converts the received signal using PAM4 modulation instead of PSM4, LR4 or CWDM4 using NRZ signals. The application of PAM4 signals on a single lambda means that a single laser can be used to transmit a complete 100G data stream. This network infrastructure eliminates the need for parallel fiber optics or WDM, thereby reducing the number of optical components required such as receivers and transmitters. The design of 100G single lambda technology is simpler, the number of optical components is significantly reduced, and manufacturing costs are reduced. 100G Lambda MSA has recognized that the cost of a single 100G lambda is at least 40% lower than the cost of four channels of 25G.

GIGALIGHE Single Lambda 100G Optical Transceiver

100GBASE-DR supports links up to 500m, while 100GBASE-FR and 100GBASE-LR support 2km and 10km respectively. The corresponding GIGALIGHT products include 100G QSFP28 DR1/FR1 and LR1 optical transceivers, including III-V family and silicon photonic versions. At the same time, GIGALIGHT also has 100G QSFP28 BIDI LR1 and ER1 based on the EML version, which can transmit 10km and 40km.

Not only that, GIGALIGHT also launched 100G single-lambda optical transceivers based on SFP56-DD form factor, including 100G SFP56-DD FR1/LR1 and ER1, which meet the transmission requirements of 2km, 20km and 30km, and are suitable for data centers, 5G communication networks, etc. application scenarios.

100G Single Lambda in 400G Network

100G Single Lambda technology is attractive because it reduces the cost of upgrading infrastructure to 400G while also opening up new possibilities for the future. In fact, this technology is used to break down 400G signals into 4×100G instead of NZR’s 8×50G. Single-channel 100G also reduces the manufacturing cost of 400G QSFP-DD optical transceivers.100G Lambda can ease the transition from 100 to 400G by reducing the structural complexity of 400G transceivers. At the same time, it will also bring great savings by reducing the number of fibers.