An optical data storage system includes a laser diode to produce at least one light beam. An inorganic, dielectric grid polarizing beam splitter is disposable in the light beam to transmit a polarized light beam, and includes a stack of film layers disposed over a substrate. Each film layer is formed of a material that is both inorganic and dielectric. Adjacent film layers have different refractive indices. At least one of the film layers is discontinuous to form a form birefringent layer with an array of parallel ribs with a pitch of less than 390 nm. A drive carries a disc medium disposed in the polarized light beam to reflect a modified light beam. The grid polarizer is disposable in the modified light beam to separate the modified light beam into a reflected beam and a transmitted beam. A photo-detector is disposable in the reflected or transmitted beam.