傳統全像儲存之繞射效率會隨多工頁數增加而導致繞射效率呈現平方 倍數下降，也就是當多工頁數為 N 頁時繞射效率將下降 N 之平方倍，將導 致儲存容量與讀取速度受限。且當前技術在嘗試多工讀取資訊時，頁間串音 限制了被讀取頁面的間距不能夠太近，而過遠的頁面間距大幅增加馬達轉 矩的要求，使高速停頓讀取再高速移動到下一個讀取位置的過程成為不可 能的任務。此外，呈現 sinc 函數的位移選擇性迫使讀取位置必須要非常接 近寫入位置，才能夠讀出足夠的繞射光強，因而大幅提高馬達對位精準度的 需求。 本論文提出一套全像儲存技術，稱為 N 倍繞射效率之體積全像多工技 術，不僅可以改善多頁多工時繞射效率受 M/#限制之情形，還可以改善位移 選擇性的函數形狀。此全像儲存多工記錄時可將多頁資訊記錄於同一位置， 可大幅提升全像儲存之儲存密度，除提升儲存密度外還能隨位移讀取同一 位置之資訊，將大幅提升讀取時的效率。 ;As the number of multiplexed pages increases, the diffraction efficiency of conventional holographic data storage systems will decrease with the square of the diffraction efficiency. That is, when the number of multiplexed pages is N pages, the diffraction efficiency will drop by the square of N, this resultsin limited storage capacity and reading speed. When conventional holographic data storage technology attempts to read multiplexed information, the crosstalk between pages will limit reading pages and make them too close together, thus, excessive page spacing greatly increases the motor torque requirements. The process of stopping high-speed reading and then moving to the next reading position at high speed becomes an impossible task. Furthermore, the shifting selectivity of the sinc function forces the reading position to be very close to the writing position in order to read the diffraction beam, which increases the requirements for motor alignment accuracy. This paper proposes a holographic data storage technology, called “N times enhancement of diffraction efficiency of Volume Holographic Multiplexing Technology”. This holographic data storage technology can record multiple pages of information at the same location during multi-task recording, which can greatly III improve the storage capacity of holographic data storage. In addition to improving storage capacity, it can also read information at the same location by shifting the hologram, which will greatly elevate the reading efficiency.
