Alignment-Free Fiber Confocal Microscope and All-Fiber Optical System for Multilayered Optical Memories

Abstract

We propose a fiber confocal microscope as an alignment-free readout system of multilayered optical memories. The fiber confocal microscope does not require fine pinhole position alignment because the fiber core is used as the point light source and the pinhole, and both of which are always located at the conjugated point. The configuration reduces the required accuracy of pinhole position alignment. The fiber confocal microscope can also achieve a compact pickup head. Recording layers in a multilayered medium could be detected with an axial resolution of approximately 900 nm. We demonstrated eight-layer readout with the fiber confocal microscope. We also propose an all-fiber recording and readout system for multilayered memories.