PLC splitters are widely used in PON and CATV networks. They help distribute fiber signal in "tree" network configurations, with one common fiber serving multiple branches. Splitters help save precious fiber strand resources, but also provide a shared media that forces a token data approach for subscribers. PLC splitters are very reliable and affordable, they come into different packages, from small thin aluminum barrels to ABS and LGX boxes and finally 19" rack mountable units. Due to a width of options for packaging, connectors and number of ports, splitters are usually made by order but turnaround is generally a week.
A datasheet explaining most models and characteristics is available for download: PLC Splitters PDF datasheet.