全像光學元件在光學連接及光纖通訊波長多工的研究

Abstract

光學連接及波長區分多工元件的執行特性主要受限於訊號的扇出密度和容 量。由於全像光學元件具有高繞射效率、組合多種光學功能及容易製作的 良好特質，可用於解決這些問題，因此，本論文研究全像光學元件在光學 連接及光纖通訊波長區分多工的應用。在光學連接元件方面，利用對稱離 軸型及基片傳輸型兩種結構，以鹵化銀和重鉻酸銨明膠體積型全像材料， 設計製作可調焦距式元件及光束壓縮元件，這些元件能夠有效地應用於光 學連接系統中。波長區分多工的功能意味著能將大量不同波長的光訊號傳 送於單一光纖中。我們利用穿透和反射式基片傳輸型全像片的布拉格繞射 、角度色散、及內部全反射傳遞特性，設計並製造具有非感應偏極高效率 、低嵌入損失、低串擾損失且多頻道傳輸容量的波長區分多工及解多工元 件。 The performance of optical interconnections and wavelength- division-multiplexing (WDM) device is limited by signal transmission fanout densities and capacity. Holographic optical elements have good characteristics for free-space optical interconnections and WDM, including high diffraction efficiency, combined several optical functions and ease of fabrication to solve these problem. In this dissertation, the large fanout optical interconnection elements that utilize the diffraction from volume hologams, and the symmetrical off-axis and substrate-mode structure have been described. Techniques for making tunable focal power elements and beam compression connectors are disscused and experimentally fabricated in bleach silver halide and dichromated gelatin emulsions. These devices should lead to more efficient optical interconnection architecture that would be more suitable for optical implementation. WDM involves the transmission of a number of different peak wavelength optical signals in pacallel ot a single optical fiber. Bragg diffraction, angular dispersion and total internal reflection propagation by substrate-mode holograms have been used to demonstrate a large channels of WDM device. The major implementations of wavelength-division- multiplexing /demultiplexing devices with transmission- and reflection-type substrate-mode grating pairs are discussed and compared with particular emphasis placed on their optical efficiency, crosstalk performance and the number of channels that may be provided. We have desiged and fabricated WDM devices that are implemented by polarization-insensitive high- efficiency substrate-mode hologram. Based on the above schemes, multi-channel devices, which exhibits low insertion loss and crosstalk attenuation, has been demonstrated. In addition, the design of WDM using the cascaded structure of substrate-mode holograms is also presented. The design can increase the transmission capacity more efficiently.