2D microlens array-based surgical microscope in optical system's exit pupil expander

The conventional surgical microscope uses eyepiece lens systems which have very small exit pupil to occur when the observer moves his head during observation, thereby obliging the observer to keep his head at a constant position while he performs the operations described above. Therefore, the conventional surgical microscope has a defect that it gives a strong feeling of fatigue when he continues observation for a long time. Two dimensional microlens array(MLA) can be used in wearable applications as exit pupil expanders to increase the size of the optical system exit pupil. Fourier optics theory was used to derive the analytical formulas, and physical optics beam propagation was used for numerical computations. The MLA's reflective surface was spaced from the other focal curve about a focal length. A dual-MLA is proved that can produces excellent exit-pupil, and it can often generate output beamlets that have a more uniform brightness.