Truly 100G passive DWDM solution – Our answer O-Band

WDM (Wavelength Division Multiplexing) is a transmission technology that uses a single optical fiber to simultaneously transmit multiple optical carriers of different wavelengths in optical fiber communications. All possible wavelengths are divided into several bands, and referring to the ITU-T standards, we know that single-mode fiber is divided into six bands. They are O, E, S, C, L, and U bands.

Did you know that the O-Band wavelength is the first wavelength band used in optical communication history? Well, yes, the O-Band wavelength is the original band with wavelengths from 1260 to 1360nm. E band can be mentioned as well as the expansion of O band, but it is rarely used. Next up is the S band. The S band is mostly used for PON (passive optical network) systems, and actually, optical fiber loss is lower than it is in the O band. The C band is, moreover, a conventional band. Why? Firstly, C stands for Conventional, but also C band has the lowest loss, which means that there is a possibility for long-distance transmission systems. C band ranges from 1530 nm to 1565nm. L band (Long wavelength Band, 1565-1625nm) is often used when the C-band is insufficient to meet the bandwidth requirements, but it also has the second lowest loss. Lastly U band, also known as ultra long band 1625-1675 nm, is not mostly used.

xWDM wavelength bands

O-band stands for Original Band, as it was the first wavelength band introduced. The O-band is extensively used for high-speed Ethernet transmission, such as IEEE 100GBASE-LR4 or 400GBASE-LR8. The O-band is known for its use of silica glass, which has a zero material dispersion wavelength. This small dispersion allows a high-speed optical transmission without dispersion compensation schemes. While using no dispersion compensation schemes, it offers advantages in both the initial investment and operation costs. In short, a lower transceiver price and lower power consumption. The 100G Passive DWDM O-Band solution is designed for customers who need more than one 100G connection over medium-length distances. Taking into account the advantages, there are some disadvantages that need to be known. Regarding the O-band dispersion is zero, and the optical fiber attenuation is increased. Because of the increased attenuation, there is a need for stronger lasers in the transmission, and products in the O-band are used only for connection over short distances.

O-band passive DWDM 100G solution allows to transmit up to 16x 100G data streams in 20/30km without the need for signal amplification!

The O-band optical wavelength range is used in many different solutions in nowadays telecommunication systems. One of them is the xWDM system, which EDGE Optics offers single-wavelength 100G QSFP28 O-band xWDM pluggable optical transceivers and passive O-band MUX / DeMUX filter equipment. Transceivers are operating over O-band with 16 wavelengths from 1295nm to 1312nm in LAN-WDM grid at 200GHz channel spacing. Single-mode G.652 optical fiber is required for these modules to operate without issues. Connecting a single-channel link from one QSFP28 directly to another QSFP28, without MUX filters, the maximum link distance can be up to 30km. But if an 8Ch MUX / DeMUX filter system is used, then due to filter insertion loss maximum link distance shrinks to 25km. And respectively with 16Ch MUX / DeMUX filter – 20km.

Passive DWDM 100G QSFP28 O-band xWDM transceivers are designed with a CAUI-4 host electrical interface, which contains 4 NRZ lines. This approach assures compatibility with most of the switch manufacturers. The 4 electrical NRZ lines are appended together with the help of an in-module gearbox to one PAM4 optical signal line with integrated FEC. This optical line is the main modulated signal source, which is driven by a laser on a specific wavelength channel.

O-band passive MUX / DeMUX filter solution allows transmitting a maximum of 1.6Tbps of data over a 20km distance. This is achieved with the solution No. 1, with 16ch MUX / DeMUX filters and all channel 100G transceivers.

Solution No 1 – Double Fiber O-Band DWDM 100G passive connection with 16x 100G-QSFP28 O-Band transceivers, and two Double Fiber O-band DWDM 16-channel passive filters:

Solution No 2 – Single Fiber O-Band DWDM 100G passive connection with 16x 100G-QSFP28 O-Band transceivers, and two Single Fiber O-band DWDM 8-channel passive filters:

EDGE Optic O-band 100G DWDM transceiver portfolio:

100G O-Band QSFP28 Optical Transceivers

For any requirements and information, be sure to contact us!