Cabling specialist achieves excellent return loss values with APC 8° angled polish of multimode MTP®/MPO connectors
Augsburg, May 19, 2020 – Rosenberger Optical Solutions & Infrastructure (Rosenberger OSI), manufacturer of innovative fiber optic cabling infrastructures in Europe, is now disclosing the outstanding innovation of the new PreCONNECT® SEDECIM cabling system after its market launch in mid-March. "The special feature of PreCONNECT® SEDECIM is that the ferrule endfaces of the MTP®/MPO 16 fibre multimode connector are 8° APC angularly polished. Due to this angled polish, the return loss could be significantly improved", reveals Harald Jungbäck, product manager for data center cabling systems at Rosenberger OSI.
APC 8° angled polish: Already proven in singlemode applications
In developing the PreCONNECT® SEDECIM, which is optimized for the 400GBASE-SR8 transmission technology, the cabling specialist uses a technology that has already proven itself in singlemode applications. The APC 8° angled polish is used from the outset for singlemode MTP®/MPO ferrule endfaces to achieve reliable return loss. In contrast to this, only the PC 0° straight polish was previously used for multimode MTP®/MPO ferrule endfaces.
Due to their PC 0° straight polish design, multimode MTP®/MPO connectors were previously particularly susceptible to performance problems caused by dirt particles, which in the past often led to unreliable return loss values. In recent years, this problem has become increasingly severe due to the sharp rise in application data rates. The introduction of reflection-sensitive PAM4 coding at 400GBASE-SR8 and other multimode applications with serial lanespeeds of 50 Gbit/s has shown its full extent.
Research from Rosenberger OSI led to innovation
"When 400GBASE-SR8 was introduced to one of the world's largest Hyperscalers in 2019, these problems were so severe that research results on the APC 8° angled polish on multimode MTP®/MPO ferrule endfaces from Rosenberger OSI were used, which were already collected in 2012. The measurements prove that multimode MTP®/MPO connectors with APC 8° angled polish, in contrast to those with PC 0° straight polish, guarantee a reliably high return loss in the application. Due to the clear facts of these tests, the Hyperscaler, also in close cooperation with the MTP® inventor and manufacturer USCONEC, decided to specify the multimode MTP®/MPO 16 ferrule endfaces APC 8°. This decision not only affected the cabling infrastructure but also the 400GBASE-SR8 Tranceiver Media Dependent Interface (MDI). There was also no discussion on this subject regarding our PreCONNECT® SEDECIM. The research results clearly speak for themselves," says Jungbäck. Thus 400GBASE-SR8 transceivers can now have both an MTP®/MPO 16 PC 0° and an MTP®/MPO 16 APC 8° as Media Dependent Interface. The distinguishing feature of the innovative MTP®/MPO multimode connector system, with 16 fibres in a row and APC 8° angled polish, is a white bend protection boot on the black connector.