Pellicle Beamsplitter

A type of beamsplitter constructed of an ultra-thin nitrocellulose membrane bonded to the lapped edge of an aluminum ring. It neither adds distance to the optical path length, nor creates ghost images due to back reflections. Although a pellicle beamsplitter is more sensitive to vibrations than a standard glass substrate beamsplitter, it does not add chromatic aberration or induce a focal shift.