本論文主要利用布拉格光纖光柵搭配光循環器等元件，設計出各種單、雙向光交叉連接器，並分析探討各光交叉連接器之傳輸特性。比起傳統陣列波導搭配光開關式光交叉連接器價格低、擴充易且新增雙向傳輸概念。在此我們提出若干種光交叉連接器之光路架構，針對其插入損失、串音干擾、傳輸功率償付值與疊加個數極限作一系列討論。
以傳統單向2×2光交叉連接器架構量測切入主題，我們以波道間距0.8 nm作為實驗標準，各切換模式下，插入損耗約在3~5 dB不等，頻帶內雜訊串音程度在-37 dB以下。對單向2×2 OXC架構加入2 m的摻鉺光纖作為補償增益介質，使成為無損的光交叉連接器，頻帶內雜訊串音程度仍可在-27.5 dB以下。利用特殊可循環光循環器的設計，進一步架構雙向2×2光交叉連接器，未補償前，各切換模式下插入損耗在4.5~5.5 dB之間，頻帶內雜訊串音程度在-34 dB以下；2 m的摻鉺光纖補償後，頻帶內雜訊串音在-34.18 dB以下。緊接著設計單向3×3光交叉連接器，各切換模式下最高的插入損耗為7.54 dB，雜訊串音在-30 dB以下，2m的摻鉺光纖功率補償後，雜訊串音仍可在-29.5 dB以下，雙向3×3光交叉連接器插入損耗為8.43 dB，雜訊串音在約-30 dB以下，3m的摻鉺光纖功率補償後，雜訊串音在-28 dB以下。單純雙向2×2與3×3光交叉連接器功率償付值皆小於0.3 dB，經過雙向單模光纖傳輸50 km，因光纖色散的原因功率償付值為1.32 dB。對傳輸中頻帶內串音與誤碼率的關係作量測，在誤碼率為10-9時，我們以功率償付值1 dB作為可忍受之極限範圍，推算出疊加之最大值，設計各光交叉連接器串聯模組數皆可在20個上下。以上結果可驗證其設計各光交叉連接器品質良好可用於傳輸。

The thesis mainly focuses on the design of uni- and bidirectional optical cross-connects (OXCs), which are based on fiber Bragg gratings (FBGs), optical circulators (OCs) and the related optical components. We also verify their characteristics in a lightwave subsystem. The issues of insertion loss, crosstalk and power penalty are discussed. Compared to array waveguide grating (AWG)-based multiplexers, our FBG-based OXCs are low-cost, easy to expand, and provide the bidirectional function.
Firstly, we measure the characteristics of a conventional 2×2 Uni-OXC which has channel spacing of 0.8 nm. For the design of Uni-OXC, 2 units of 3-port OCs and numerous tunable FBGs are included. The original central wavelengths of FBGs are matched to the corresponding wavelength division multiplexing (WDM) chanels. The insertion loss for either corss-connect or pass-through state is around 3~5 dB. The intraband crosstalk always maintains -37 dB or even lower. In order to make the OXCs as lossless devices, one piece of erbium-doped fiber (EDF) in 2 meters with small pump power are included in the OXC for power compensated purpose. The intraband crosstalk is still less than -27.5 dB. By adjusting the signals direction for arrival ot leaving the OCs, the function characteristics of 2×2 Bi-OXC are demonstrated. The power compensation is considered in a similar way as that of a 2x2 Uni-OXC. The intraband crosstalk is less than -34 dB in original. Using EDF to compensate the insertion loss, the intraband crosstalk is still less than -34.18 dB. The design of a 3×3 Uni-OXC is considered in a similar way as that of a 2x2 Uni-OXC. The insertion loss for a 3x3 OXC is around 7.54 dB. The intraband crosstalk is less than -30 dB in original. Using EDF to compensate the power loss, the intraband crosstalk is still less than -28 dB. For BER performance measurement the Bi-OXCs in 2x2 scale and 3x3 scale, The modulation speed up to 10 Gb/s, in non-return-to-zero (NRZ) format, is adopted. In back-to-back configuration with either OXC insert, the power penalty @10-9 BER is less than 0.3 dB. The power penalty will increase to 1.32 dB in 50 km standard fiber transmission, it is mainly due to the chromatic dispersion effect. Under the criteria of 1.0 dB power penalty @10-9 BER, the maximum allowable cascading OXC stages is up to 16. Note that the value is for a certain signal reflected by two individual FBGs. With high-quality and flexible characeterisitcs, the OXCs may find potential application in optical networks and lightwavel transmission.

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