全像資訊系統與應用

Abstract

本計劃旨在研究全像資訊光學系統的基本特性及其應用，並以系統容量 及誤碼率兩個參數來定量評估全像系統，建立設計與性能評估的準則。 我們將以本實驗室過去融合光波繞射與通訊系統所建立之資訊系統觀念 為主軸，深入探討全像光學在資訊儲存、處理、與顯示之基本特性與應用， 建立全像光學資訊系統之設計、評估、與應用基礎。具體言之，我們將以全 像資訊的三個題目做為研究對象: (1). 光學像差對全像儲存系統之影響；(2). 雙波長全像紀錄技術與應用；(3). 電腦全像顯示技術之先期研究。三年期間， 將以理論推導、電腦模擬、及光學實驗交互驗證。 光學像差方面，我們將推導各種賽得像差產生之點擴散函數，及其對應 之概率分佈函數，據之求出系統容量及誤碼率，以評估各別像差之影響，並 以光學設計優化之。雙波長全像紀錄技術方面，將探討摻雜過渡金屬元素之 硫化物光折變晶體、以及本實驗室研製之光感高分子材料的雙波長全像紀錄 特性，應用於動態體積全像資訊儲存，以及研製波長多工之光纖通信(DWDM) 系統的濾波分頻模組(wavelength add-drop module, WADM)，並以系統容量及 誤碼率評估模組功能。電腦全像顯示方面，我們將以無透鏡投影系統為對象， 探討電腦全像顯示器的可行性。我們將探討全像之計算、產生、顯示、與成 像技術，並以系統誤碼率評估其性能。我們也會以複合全像之觀念探討電腦 全像3D 顯示之可行性。 儲存、處理、與顯示三個項目乃是全像光資訊系統之主要內涵。因此， 預期以上之學理以及各項研究成果，將可應用到其他全像資訊光學以及數位 全像系統。

The goal of this research is to perform comprehensive investigations on holographic information systems and applications. Storage capacity and bit error rate (BER), which were established in our previous research, will be used as synergic system metrics for the design and evaluation of the holographic systems. Three major holographic information systems will be investigated in this project: (1). The influence of optical aberrations on holographic data storage; (2). Technique and applications of two-wavelength holographic recording; (3). Feasibility of using computer holograms for projection displays. On the first topic, we shall derive the point spread function as a function of the Seidal aberrations of the holographic storage system. Then, the probability distribution function of the output signals will be found, and the corresponding storage capacity and BER can be calculated. The performance of the holographic system can thus be evalueted, and the influence of the aberrations can be quantitatively determined. On the two-wavelength holographic recording, we shall derive the dynamic equations based on the band-transport model of photorefractive crystals. The dynamic behavior of the hologram formation and fixing will be computer simulated, and experimentally characterized. We shall investigate materials for the two-wavelength recording including rare-earth elements-doped BSO and BTO photorefractive crystals as well as the PQ/PMMA photopolymers which is fabricated in our laboratory. We shall apply the two-wavelength holograms to design and fabricate a WADM (wavelength add-drop multiplexer) in DWDM communication systems. Again, the storage capacity and BER of the two-wavelength holograms will be estimated. On the feasibility of using computer holograms for a lens-less projection display, we shall perform a parametric investigation on how the computing algorithms, encoding techniques, and SLM quality affect the imaging characteristics. A 3D display by use of multiplexed holograms will also be designed and characterized. . The methodology of using the system metrics for the design and evaluation of holographic information systems can be extended to other digital holographic systems.