Carbon nanotubes (CNTs) make an ideal one-dimensional (1D) material platform for the exploration of novel physical phenomena under extremely strong quantum confinement. The 1D character of electrons, phonons and excitons in individual CNTs features extraordinary electronic, thermal and optical properties. Since their discovery in 1991, they have been continuing to attract interest in various disciplines, including chemistry, materials science, physics and engineering. However, the macroscopic manifestation of 1D properties is still limited, despite significant efforts for decades. Recently, a controlled vacuum filtration method has been developed for the preparation of wafer-scale films of crystalline chirality-enriched CNTs, and such films have enabled exciting new fundamental studies and applications. In this review, we will first discuss the controlled vacuum filtration technique, and then summarize recent discoveries in optical spectroscopy studies and optoelectronic device applications using films prepared by this technique.