在90度架構下利用鈮酸鋰晶體之串接式體積全像濾波器做為光通訊波長多工解多工器之研究

Cascaded Volume Holographic Filters for WDM in LiNbO3 Crystals with 90 degree Geometry

陳文豪(Wen-Hao Chen)

指導教授 ： 蘇威佳

大同大學/電機資訊學院/光電工程研究所/碩士(2004年)

摘要

摘要 在光纖通訊中系統中，藉由使用高密度分波長多工的技術可以擴大傳輸的容量。此技術需要光學波長濾波器將不同頻道的訊號做多工或解多工。本文中呈現以串接多個全像濾波器為基礎的解多工元件。我們利用在一個鈮酸鋰晶體中建立一個單一的全像布拉格光柵來產生濾波器。每個濾波器可以將高密度分波長多工中的特定頻道(波長在1550nm 附近)以90 度架構濾出。經由我們的設計，晶體的動態範圍可以有效地被利用，因此可以增加每個頻道的繞射強度。另外，整個元件可以很緊密且簡潔。對於此元件，我們可以加入並串接多個不同的濾波器來增加其頻道數，其中一個濾波器對應一個頻道。而光柵的建立是利用鈮酸鋰晶體的光折變效應紀錄兩道綠色雷射光之干涉來完成。 此篇論文將呈現 : (1)建立可將波長在1550nm 附近的光以90度架構繞射出來的光柵之實驗方法。(2)作用於波長範圍1510，1530，1550，及1570nm 的單一頻道濾波器之特性。(3)兩個頻道的解多工器(頻寬可達到1nm，且頻道的間距可降至1nm)。

關鍵字

波長解多工器 ； 高密度分波長多工 ； 光學波長濾波器

並列摘要

ABSTRATE
The transmission capacity in optical fiber communication system is enhanced via dense wavelength division multiplexing (DWDM) for technique. This technique needs optical wavelength filters for multiplexing or demultiplexing the different transmission signals. In this thesis we present a demultiplexer device based on cascaded holographic filters. The filters were established by constructing a single volume holographic Bragg gating in a single lithium niobate crystal. Each filter drops the light from a specific DWDM channel (wavelengths of ~1550nm) in 90 degree geometry. In our design, the dynamic range can be efficiently used and thus the diffraction intensities of each channel can be increased. In addition, the device could be compact. In this device, channel number can be increased by cascading different filters. Each
filter addresses a channel. The gratings are recorded through the photorefractive effect by interference of two green laser beams. In this thesis we present: (1) the experimental methods of building the gratings for dropping the wavelengths around 1550nm in 90 degree geometry. (2) The characterization of the one-channel filters working at 1510, 1530,1550, and 1570nm respectively. (3) A two-channel demultiplexer demonstrator (bandwidth down to 1nm, channel spacing down to 1nm).

並列關鍵字

Demultiplexer ； DWDM ； Volume Holographic Filter

參考文獻

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