Research On Design Theory And Method Of Multifunctional Intergrated Liquid Crystal Light-field Modulation Devices

Light is an important substance that makes up our world.Light field modulation is essential to exploit the unique advantages of photons as information and energy carriers.Effective spatial regulation of the optical field,especially the two important properties of the phase and polarization state of the optical field,and thus the creation of new spatially structured optical fields with peculiar properties,provides new ideas for manipulating the light propagation behavior.The optical anisotropy,high transmittance,and the ability to realize complex structures of liquid crystals have led to their widespread use in optical devices.Because the manufacturing process of liquid crystal devices can combine cleanliness,simplicity,versatility,inexpensiveness and ease of use,the research of liquid crystal optical devices can promote the application of optical field modulation to a deeper level,and the phase integration and electrical control coordinatability of liquid crystal greatly broaden the application of liquid crystal devices in the field of optical field modulation.In this paper,we combine light orientation technology with liquid crystal devices to study the design,preparation and functional expansion of liquid crystal optical field modulation devices.The main innovations achieved are as follows.1.Based on the conventional Gaisberg-Saxon(G-S)algorithm,a new iterative G-S algorithm based on the synchronous tunability of the polarization phase of the liquid crystal optical device is proposed,and this algorithm is applied to the optimization of the target surface optical intensity uniformity to obtain a better uniform far-field focal spot compared with the conventional beam leveling technique.Further,the feasibility of this liquid crystal-based beam leveling technique is initially experimentally verified by using the light-controlled orientation technique of liquid crystal.This study can be applied to the design of different classes of polarization-phase optical elements,which have important potential applications in fields such as spatial beam shaping.2.The generalized PB-phase(geometric phase)interference theory is proposed theoretically.Based on the fact that the superposition of multiple liquid crystal devices in a coaxial optical path can realize the spatial modulation of PB-phases of circularly polarized light with different spins,the interference using these two beams of circularly polarized light with different phase distributions can realize the structured orientation of phase devices with complex liquid crystal structures.This single-exposure approach is cheaper than the conventional preparation method,with a simpler operation method and high reproducibility.This method is an important reference for the future scale production of liquid crystal light field modulated devices.3.The functional expansion of the liquid crystal optical field modulation device is studied from three aspects: multifunctional integration of the device,electronically adjustable dynamics,and operating bandwidth expansion.Based on the phase integrability of liquid crystal devices,a device integrating two phase functions,linear gradient phase and lens phase,is proposed and prepared,which can realize the lens effect with separable focus in three-dimensional space,and the focal length of the lens system can be adjusted in three-dimensional space by integrating with the conventional lens;The use of electronically controlled liquid crystal polarizer(q-plate)and wave sheet to generate mixed-order Pongare sphere on arbitrary The method of vector vortex beam is proposed and theoretically and experimentally verified;diffractive devices for phase modulation are generally limited to single wavelength or relatively narrow operating bandwidth,in order to expand the broad-spectrum applicability of liquid crystal optical field modulation devices,a new optical system is proposed,which can realize pure phase modulation in a broad spectrum by combining liquid crystal optical field modulation devices and liquid crystal polarization grids.Also,by combining the electrically controlled liquid crystal devices,independent modulation of intensity can be achieved.The improved polarization phase synchronization iterative G-S algorithm proposed in this thesis provides an algorithmic basis for the basic design of micro and nano optical field modulation devices such as liquid crystals;the preparation process of generalized PB phase interference greatly simplifies the production steps of structured liquid crystal devices and is expected to save production costs;the extended application of phase integrability,electrically controllable coordination,and broad-spectrum applicability of liquid crystal optical field modulation devices based on the The expanded applications based on the phase-integratability,electrically coordinable,and broad-spectrum applicability of liquid crystal light field modulation devices broaden the application areas of liquid crystal light field modulation devices.All of the above work provides an important reference value for the future batch,industrial and largescale production and application of structured liquid crystal devices.