Research On Multimode Liquid Crystal Microstructure Driven And Controlled Electrically And The Imaging Technology

Conventional imaging optical systems can achieve the operations of the focus adjustment through changing the axial distance between lenses, and the focus swing through finely calibrating the transverse position shift between lenses. Their typical defects include:the volume and weight being large, being difficult to miniaturize imaging structures, existing a relatively large mechanical inertia, being unable to rapidly or even real-time response the variance generated, easily generating the position or shape variance under the condition of hypersonic movement or strong vibration, being hard to restore or calibrate timely, and demonstrating an insufficient controlling-light ability in micro-nano-sacle based on the light field compressing. The above problems are difficult to be solved thoroughly by traditional optical means. The technique of electrically controlled liquid crystal microlens (LCM) developed in this dissertation provides a new technological way and then solution to get rid of the defects mentioned above for imaging detection applications. According to the special electro-photo-properties of the nematic LC material driven electrically, the functioned LC micro structures with multimode controlling-light performance is developed. Multimode controlling-light means that the converged beams outfrom main optical system are continuously adjusted through several independent means (modes) for chipped imaging detection, including matching and adjusting the parameters of beams such as the wavefront, the spectrum, the wavevector, the polarization, the energy flow, and the light convergence and divergence. The key parameters, for instance, the imaging field of view, the depth of focus, the optical aperture, and the light intensity distribution formed over the focal plane, can be adjusted through a dual-mode (convergence and divergence) LCM driven electrically. The solidification and adjustment of the spectral components of beams from targets through the electrically controlled liquid crystal Fabry-Perot (LC-FP) structure can be achieved. The adjustment spatial resolution can be realized through electrically selecting the format of LCM array. The main contents are as follows:Firstly, according to the elastic continuum theory of LC material, the research of LCM driven by the patterned electrode is conducted. The LCMs with several types of patterned electrode are simulated. The electric field distribution in the LC layer, and the beam phase delay, and the director distribution of LC materials in electric field applied, are analyzed. The several prototyped LCMs based on the patterned electrode, are fabricated, and then the common optical properties are acquired. Secondly, based on the simulation of the electrical field distribution stimulated in LC layer, a LCM with four strip sub-electrode distributed symmetrically and utilized to perform the operation of electrically adjusting and swinging focus (EAASF), is developed. The prototyped EAASF-LCM is designed and fabricated, and then the common optical performances are also acquired. The typical parameters and features of the device fabricated include:the maximum swing scale of focus being80μm, and the full width at half maximum height of focus spot being12μm, and the focus being able to not only move along the optical axis but also swing over the focal plane. Based on a single layer of patterned electrode, an EAASF-LCM with a double-layer patterned electrode is further developed. The principle of demonstrating EAASF operation is analyzed, as well as the relation between the effective optical aperture shaped after applying an electrical driving signal and design parameters. The relation between the focal length of LCMs with different aperture and the applied driving voltage, are tested, as well as the relation between the circular aperture with different size and the driving voltage signal.According to the application requirements, both dual-mode (light convergence and divergence) integrated and coupled LCM arrays are developed, respectively. This type of the prototyped LCMs are designed and fabricated, and thus the common optical performances are obtained. The experiments show that the developed microlenses demonstrate not only the dual-mode controlling-light function but also an ability of resisting disturbing beams. Based on the electrically focusing characteristics of LCMs, an addressable controlling-light bionic ommateum LCM array is developed, and then the EAASF operation and electrically selecting optical aperture can be realized. In addition, the crucial fabrication processes of functioned LCMs are summarized, and the correspondent electrical setups for driving arrayed LCMs are also developed.Finally, a country-needed basic study on infrared electrically controlled LC-FP device and dual-mode microlenses are carried out. Based on ZnSe substrate coated with an aluminum film, an infrared LC-FP architecture for spectral imaging and then the needed LCMs are developed. Their common infrared optical performances are tested, so as to establish a foundation for continuously conducting correspondent research.