論文摘要

在長波長掺鉺光纖放大器的設計上，必須要具備高增益、低雜訊以及增益平坦化，在多級EDFA的架構下，前置放大器所擔任的角色，則同時主宰了這三個最重要的條件。因此在設計上，我們以兩級放大器為架構基礎，並加上C/L WDM，讓大部份吸收能量的波長侷限在L band之內，如此就能讓L band的各個訊號能更加直接地獲得pump power所提供的能量，而更進一步地減小後級放大器的雜訊所產生的影響。
在架構上，前置放大器主要以980nm pump laser為激發光源，並用低濃度的EDF使整體populations大部份維持在高能階，以使獲得較大增益並降低雜訊的產生；另外再加上C/L WDM使大部份能量集中在L band 的波長，並依掺光纖的長度還有pump power的大小，來做好前置放大器的最佳化。最後再加上1480nm high pump power，以使訊號在後級能夠獲得最大的能量，進而得到較高的增益。在此系統下，以總功率100mW為前提之下，對整個EDFA系統而言，雜訊指數都能獲得一定程度的水準，比起一級的前置放大器，而增益則是能高達1.5dB的幅度，可算是一個高增益、低雜訊並具平坦化的放大器。

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