A novel design of optical path length magnifier for ocular axial length measurement in an optical biometer

A novel design of an optical path length modulator is reported for ocular axial length measurement in an optical biometer. The relative optical path length modulator is designed to achieve a large optical path length change linearly over 52 mm with a tiny, short translation stage movement of 3 mm to cover the entire axial lengths of all patients from infant to adult in an optical biometer. This design demonstrates a good benefit for the long-range scanning of ocular axial length from cornea to retina with small translation stage movement of reference arm.