Pellicle Beamsplitter, 74.9 mm OD, 51.6 mm CA, VIS Coated

The PBS-2C Pellicle Beamsplitter is 74.9 mm in diameter with a 51.6 mm Clear Aperture in a 12.7 mm thick housing. This coated pellicle provides equal reflectance and transmission over the visible range by means of a neutral, semi-absorbing coating. The R/T curves below show average values, eliminating the often confusing sinusoidal oscillation due to interference. A ±5% wavelength dependent oscillation is superimposed on all curves. This pellicle has roughly a 50/50 split in transmission and reflectance in the visible wavelength range. Pellicle beamsplitters are ultra-lightweight components that virtually eliminate multiple reflections commonly associated with thicker glass beamsplitters. Pellicles are manufactured by stretching a 5 µm thick polymer membrane (index=1.47 @ 550 nm) over a flat metal frame. The extreme thinness eliminates secondary reflections by making them coincident with the original beam. Multiple wavelength versatility is an added benefit of an ultra-thin reflective membrane.