With　the　rapid　advancement　of　high-speed　communication　and　computational　technologies,　AR　and　VR　are　regarded　as　next-generation　platforms　for　immersive　human-digital　interaction.　Polarization　Volume　Gratings　(PVGs)　is　a　game-changing　breakthrough　in　the　fast-growing　field　of　augmented　reality　and　virtual　reality　(AR/VR),　considerably　advancing　holographic　waveguide　applications.　However,　replicating　the　sophisticated　performance　of　human　vision　while　keeping　tiny　and　lightweight　near-eye　display　modules　is　a　huge　problem　for　optical　engineers.　Recent　advances　in　holographic　optical　elements　(HOEs)　and　lithography-enabled　devices　are　highlighted　as　novel　approaches　to　overcoming　classic　optical　restrictions　in　AR　and　VR　systems.　High-resolution-density　and　high-brightness　Liquid　Crystal　(LC)　technology　is　a　promising　picture　source　for　see-through　AR　displays,　particularly　in　bright　environments.　This　comprehensive　study　investigates　the　emerging　significance　of　planar　and　ultrathin　diffractive　LC　polarization　optical　elements　in　AR　and　VR.　Ultrathin　planar　diffractive　LC　optical　elements,　like　reflective　phase　LC　gratings,　geometric　phase　LC　grating　and　lens,　have　proven　useful　in　AR　and　VR　for　a　variety　of　purposes,　including　Exit　Pupil　Expansion　(EPE),　enlightening　field　of　view　(FOV),　reducing　chromatic　aberrations,　and　achieving　gaze-matched　Maxwellian　displays　through　dynamic　pupil　steering.　This　analysis　concludes　with　a　discussion　of　future　research　directions,　paving　the　way　for　the　next　generation　of　advances　in　photonic　devices　for　AR　and　VR　displays.