在頻域振幅編碼的光分碼多工(SAC-OCDMA)網路中，頻譜平坦補償(Spectral Flatness Compensation, SFC)近來被研究在以陣列波導光柵(Arrayed-Waveguide Grating, AWG)所形成的編解碼器上，因為每一個網路使用者有著不同的簽署碼及分布在不同的頻譜波段，而由於非同調光源頻譜的不平坦將會導致嚴重的多重存取干擾(Multiple-Access Interference, MAI)，因此我們提出了一個補償頻譜不平坦的簡單方法去降低多重存取干擾。藉由安排相同的碼型在不同的頻譜波段，從陣列波導光柵編解碼器所編出的頻譜波長功率將會非同調地相加在光偵測器端基於陣列波導光柵的自由頻譜區域特性(Free-Spectral Range, FSR)，進而去達到每個頻譜波長功率幾乎相等。最後我們所提出的頻譜平坦補償方法經模擬分析出來的訊號雜訊比結果遠優於未補償的。
一個頻譜平坦補償技術，實現在頻域振幅編碼的光分碼多工網路中，我們使用了參鉺光纖放大器所發出的自發性輻射放射光源(ER-ASE)、循環器、星狀耦合器、寬頻的啁啾布拉格光柵(Chirped-FBG)以及陣列波導光柵去作頻譜不平坦的補償，系統當中所使用的簽署碼是最大長度序列碼(M-sequence Codes)，最後再去做平衡檢測得到使用者所傳的資訊。基於頻譜平坦補償實驗驗證，補償的系統性能優於未補償的系統。

Spectrum compensation over an arrayed-waveguide grating (AWG)-based optical code-division multiple-access (OCDMA) network coder/decoder (codec) is investigated. Since each network user with different signature address code has different spectral distribution, the sliced spectral power is non-equal that will cause multiple-access interference (MAI) due to the non-flattened spectra of ASE source. Flatness compensation scheme is proposed to solve the MAI effects induced by non-flattened spectra. By arranging the same coding pattern on different coding bands, spectral chips from AWG coder/decoder will incoherently power summed by FSR (free-spectral range) characteristic of AWG in the photo-detectors to approach a more flattened power level. Signal-to- interference ratio (SIR) performances are evaluated with such compensation method for the discussed OCDMA network codec.
A realizable technique of spectral flatness compensation (SFC) in spectral-amplitude- coding OCDMA (SAC-OCDMA) system consists of ASE incoherent broadband source, circulators, star couplers, chirped fiber Bragg gratings (chirped-FBGs) and AWGs for encoding/decoding of unipolar M-sequence codes with balanced detection. Based on spectral flatness compensation (SFC), it is experimentally demonstrated that the performance of such system is greater than the conventional system without SFC.

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