Optically active pi-conjugated oligo(p-phenylene ethynylene)dimers with a planar chiral 4,7,12,15-tetrasubstituted [2.2]paracyclophane were synthesized. We investigated the optical and chiroptical properties of the racemic and optically active compounds by UV-vis absorption, photoluminescence (PL), circular dichroism (CD), and circularly polarized luminescence (CPL) measurements in the ground and excited states. Aggregates were prepared by the self-assembly in the mixed CHCl3/MeOH solution, a spin-coated film, a drop-cast film, and the annealed films. In the dilute solution, the dimers exhibited good chiroptical properties, such as dissymmetry factors (gabs and glum) in 10(-3) order, large absorption coefficient, and high absolute PL quantum efficiency. In the aggregation state, UV-vis absorption and PL measurements suggested that one of the dimers formed J-aggregates and the others constructed parallel H-aggregates or inclined H-aggregates as kinetically stable self-assemblies. Those differences were caused by the length of pi-conjugation and the strength of the intermolecular pi-pi interaction. Transmission electron microscope (TEM) observations indicated the formation of the regular aggregates, and the aggregates made fiber structure. The spin-coated films and drop-cast films showed opposite CPL signal, and the values of dissymmetry factors reached 10(-2) order. The annealing process provided the thermodynamically stable forms to the films, and the glum values of the drop-cast thick films were drastically enhanced. Consequently, the glum values reached 10(-1) order (maximum: vertical bar delta(lum)vertical bar = 0.27). Those are one of the largest glum values of the organic compounds in the self-assembly system. All properties observed in this study are attributed to the planar and high symmetrical X-shaped structure of the planar chiral 4,7,12,15-tetrasubstituted [2.2]paracyclophane framework. This is the first report realizing glum in 10(-1) order using the self-assembly system based on planar chirality as the only chiral source.