Metasurface utilizes artificial microresonators to control the wavefront of classical electromagnetic waves which results in different fruitful applications such as negative index materials, holograms, and perfect absorbers. This thesis explores the interaction between quantum optical states and lossy metasurfaces, providing theoretical and experimental analysis. I first establish the foundation by examining quantum scattering processes using the effective Lindblad master equation. We uncover the equivalence between exceptional points (EPs) in this equation, termed Liouvillian EPs (LEPs), and those in classical scattering matrices. I further extend the discussion to quantum-only LEPs (qLEPs) where the LEP does not have a classical EP counterpart. Such qLEP is simulated by a metasurface that performs unitary operations in synthetic Hilbert spaces and also a quantum computer. This highlights the usefulness of metasurfaces in quantum non-Hermitian physics. I will develop a heralded hologram generated by metasurface, where the hologram content is due to interference of two classical holograms in which the interference is controlled by a quantum heralding process. I also investigate biphoton holograms generated by metasurface, which is observable with biphoton state input. I also propose a metasurface displaying distinct holograms for coherent and biphoton state inputs, suggesting for cryptography purposes by hiding the biphoton holograms. This demonstrates the significance of metasurfaces in manipulating quantum states. Finally, I focus on the application of quantum EPs in quantum interferometers for sensing, achieving sensitivity comparable to the optimal signal-to-noise ratio and broadening the operational regime of these devices. This thesis offers a detailed theoretical framework and xviii practical insights into the non-Hermitian metasurface interactions with quantum states and expanding their application from classical wave physics to novel quantum phenomena.