Cluster states, composed of multiple entangled photons, are essential states for the scaling of optical quantum computing. In our lab, we have performed the generation of polarization-encoded, individually-addressable photons in linear cluster states occupying a single spatial mode by employing a single entangling-gate in a fiber loop configuration to sequentially entangle an ever-growing stream of photons. This apparatus enabled the generation of linear cluster states up to four photons in a single-mode fiber. Larger cluster states are currently in development.