Diamond-like carbon(DLC) films were directly deposited onto germanium(Ge) witness pieces and lenses by a capacitively coupled 13.56 MHz RF glow discharge plasma with $CH_4$ gas. The characterizations of DLC films were measured using a Raman and FTIR spectrometer. The configuration of Raman and FTIR spectra had a traditional shape. The IR transmittance was measured using an IR spectrophotometer. The maximum values of the IR transmission of Ge with the DLC/Ge/DLC, DLC/Ge/BBAR (broad band antireflection), DLC/Ge, and BBAR/Ge structures are 98%, 93%, 64%, and 63.5%, respectively, which come up to the theoretical values. The uniform DLC films were obtained by a rotation of the cathode at certain conditions.