應用於藍光讀寫頭之同軸式光柵設計與製作反向相容是光儲存系統進展之一重要議題。其在過去之 DVD 系統已非常明顯，也在現今之藍光系統顯露無遺。在這發展中，單體雙波長積體式之雷射二極體(TWIN-LD)是一重要改進，其整合兩雷射共振腔於單一封裝，一為650nm 雷射波長，另一則為780nm 雷射波長。此進展大幅簡化光學系統之設計，將原本複雜之架構變成單一光路之架構。也因此降低製造成本與組裝之複雜度。在此情形下，單體三波長積體式雷射二極體亦正積極地被開發中，在未來即將被應用於實現單一光路具有三種雷射波長的光學讀寫頭系統上。鑑於此，本計畫結合台睿科技公司之合作，進行可適用於單一光路三波長光學讀寫頭之使用的同軸光柵設計與製作。我們將採用二維分區陣列式之概念來設計此同軸光柵，藉由純量繞射理論與光學模擬軟體之分析，得到最佳之同軸光柵設計。進而經由微製造之技術製作此同軸光柵。最後，此元件更將被組裝於雷射二極體上以實現單一光路三波長光學讀寫頭之目的。Design and fabrication of in-line gratings for the Blu-ray optical pickup headBackward compatibility is one of the important issues on the progress of optical storagesystems. It had been very clear on the past DVD development and is also apparent in thecurrent Blu-ray systems. One important improvement is the birth of the monolithictwo-wavelength integrated laser diode (TWIN-LD). It integrates two laser cavities, one forthe 650 nm wavelength and the other for the 780nm wavelength, in a single package. Thatgreatly simplifies the optical system design from two complicated paths to one simple pathand therefore reduces the manufacturing cost as well as the assembly complexity. Under thecircumstances, the monolithic three-wavelength integrated laser diode is currentlyaggressively developed. It will be soon applied to the Blu-ray system for achieving asingle-path optical pickup head with three laser wavelengths.Under the consideration, this project is proposed to develop an in-line grating, which isapplicable to the use of the single-path optical pickup head with three laser wavelengths, inconjunction with the support of TopRay Technology Inc. We will adopt the concept oftwo-dimensional segmented matrix to design the in-line grating pattern. With the analysis ofscalar diffraction theory and optical simulation software, the optimized design will beobtained. Furthermore, the grating will be produced by using the technology of microfabrication. Finally, this device will be assembled to the laser diode for realizing asingle-path three-wavelength optical pickup head
