very small form factor (VSFF)
The development of FO connectors is continuously moving towards smaller, space-saving designs. If SFF connectors, Small Form Factor (SFF), were already extremely compact, the coming generation of VSFF connectors, Very Small Form Factor (VSFF), will be a lot smaller. However, some are still under development.
The aim of the next generation of VSFF connectors is to further increase the connection density in data centers. For this reason, the VSFF connectors, which are only a few millimeters in size, have a modular design as duplex connectors and can be combined to form a multi-fiber connector.
Various VSFF connectors have been developed, such as the CS connector, MDC connector and SN connector, but these have not found market acceptance. For example, if you take the CS connector, which can be compared to the LC connector, the total connector is only 7 mm x 7.8 mm. The distance between the two monomode fibers is only 3.8 mm. In comparison, the LC connector has dimensions of 10.7 mm x 12.3 mm and a pitch distance of 6.25 mm. It can be seen from these data that the CS connector requires less than half the space of the LC connector. The CS connector is designed for the 200GBase-FR2 interface of200 Gigabit Ethernet.
The MDC connector can be combined modularly to form a multi-fiber connector. At 3.1 mm, the distance between the optical fibers is even smaller than for the CS connector.