[[alternative]]Optical Pickup Head Design Using Cylindrical Solid Immersion Lens and Nanometer Aperture Probe Array

碩士電機工程學系[[abstract]]在光儲存技術中，為了得到較高的儲存密度，必需縮小記錄的光點克服繞射極限，所以有學者提出了近場光學理論來克服繞射極限。在近場光學中，奈米大小的孔徑與固態浸沒透鏡(solid immersion lens)都能使在遠場光學中的記錄光點克服繞射極限，達到縮小光點的目的，但是奈米孔的光穿透率非常低，若能將固態浸沒透鏡與奈米孔徑整合使用，可有效的提升其光穿透率。值得注意的一點是此二者的大小差異過大，要將二者結合對準使用是極為困難的事，所以在本論文提出的方法是設計一個圓柱型的固態浸沒透鏡，此透鏡所產生的光點為一直線，再設計出一個奈米大小的孔陣列，以圓柱型固態浸沒透鏡產生的直線光點掃描在奈米孔陣列(nanometer aperture probe)上，此方法可免除將二者對準的問題也可達到多光點寫入的好處，固態浸沒透鏡底部全反射所產生的消散波(evanescent wave)，其衰減的距離與奈米孔徑的長度有很密切的關係，若奈米孔徑的長度過長，則固態浸沒透鏡底部所產生的消散波就無法順利的耦合至碟片，所以必需優化適合的奈米孔徑開口大小及長度，才能光點使強度提升，之後再加入微透鏡與微圓柱透鏡於奈米孔徑上方，以加大收光面積及做二次聚焦的作動，而提升光強度，除此之外也探討其極化現象與消散波強度之關係。[[abstract]]Smaller recording spot size is a key factor to overcome the diffraction limit posed on high-density optical storage technology. Near-field theory is proposed to overcome the limit by using nanometer aperture probe and solid immersion lens (SIL). However, the optical transmission ratio is low by applying the nanometer aperture probe. The use of SIL may be a solution to this problem, and the alignment will be difficult because of the size mismatch. The cylindrical solid immersion lens and the nanometer aperture probe are proposed in this research in order to improve misalignment. For the optimization of the size of the nanometer aperture probe, the total internal reflections in the SIL and evanescent wave propagation have to be calculated. The use of micro lens and cylindrical lens will also increase the optical transmission. In this research, the optical transmission of nanometer aperture probe is improved by 25 times on the basis of luminous flux. Moreover, the intensity of polarized evanescent wave in this application is studied