Abstract: A method for replicating a holographic optical element and a holographic optical element replicated thereby are provided. The holographic optical element is larger than a master. The master has a holographic grating pattern generated on the master by interference of the reflected, diffracted or transmitted beam generated by irradiating the master having a specific diffraction grating pattern formed thereon with a laser beam.

Abstract: The present disclosure provides a waveguide display apparatus. The waveguide waveguide display apparatus of the present disclosure is a waveguide display apparatus for correcting curved surface reflection distortion, the waveguide display apparatus including a waveguide for guiding light inputted from the outside; a first diffractive optical element disposed at the waveguide, and diffracting the light inputted from the outside to the inside of the waveguide; and a second diffractive optical element disposed at the waveguide, and diffracting the light guided by the waveguide to output a plurality of diffracted lights in a direction of a curved surface reflector located outside, wherein the second diffractive optical element has a structure of a diffraction grating corresponding to a curvature of the curved surface reflector such that the diffracted lights are reflected at different locations of the curved surface reflector in directions parallel to each other.

Abstract: An audio recording management method includes creating a text transcript of an audio recording by converting speech to text, matching and managing the text transcript and a memo written during recording or playback of the audio, and providing the text transcript in connection with the memo.