Fiber doesn’t use a DSLAM. That is only for DSL. Typically, fiber use an optical splitter in a fiber distribution hub at a neighborhood node that then gets aggregated into a multi-fiber cable that goes back to the central office. This is called a PON or Passive Optical Network. It’s vastly cheaper than having an active fiber switch in the local node that then goes back the CO that would then require much more cable. (The latter is often how business fiber with high SLAs and guaranteed bandwidth is configured, though.)
In fact, PONs often use multiple, tiered optical splitters to more cheaply get fiber to more homes. PONs do have advantages, though — it’s passive so requires no power along the signal path which makes it again cheaper and potentially more reliable.
But no DSLAM in sight.