無線光分碼多工系統於不同偏振光之環境測試

本研究採用一種基於頻譜振幅編碼之光分碼多重擷取(Spectral Amplitude Coding Optical Code Division Multiple Access,SAC OCDMA)的架構，使用者的編碼器與解碼器皆以光纖布拉格光柵(Fiber Bragg Grating, FBG)完成。編碼器光源為超高亮度發光二極體(Super luminescent Diode, SLD)，光源經過布拉格光柵進行編碼。在使用者編碼配置完成後，利用電光調變器(Electro Optical Modulator, EOM)加入類比/數位信號，並在自由空間(Free Space)中發送訊號。光纖輸出的光為近線性偏振光，調整線路彎曲程度會造成光的偏振態改變，並造成功率的改變，在傳輸時須將功率調整到最高後才進行傳輸，所以調整四次線路並以最高功率的線路狀態進行後續的實驗。自由空間架構在一般常溫空氣介質以及霧氣。在訊號發射端加入偏振片後進行傳輸，偏振片角度每隔30°調整一次。信號經過自由空間後送到解碼器將信號擷取出。在本研究中，在霧氣產生器所產生之霧氣中傳輸的環境測試，並加入偏振片調整偏振態。測得結果不同偏振態在傳輸過程中的信號變化。

關鍵字

光分碼多工；布拉格光纖光柵；環境測試

並列摘要

This study adopted the architecture of spectral amplitude coding optical code division multiple access to capture the electric signal frequencies inputted into an electro optic modulator (EOM). The encoders and decoders of the users were designed by using fiber Bragg gratings (FBGs). The light source of encoder is super luminescent diode, source is encoded after getting through fiber Bragg gratings. After the user encoding configuration was completed, an EOM was adopted to add analog/digital signals and transmit them in free space to the decoder for capture. The output of light from optical fiber is nearly linearly polarized light.Adjusting the optical fiber of flexural degree caused light of polarization state to chage, and caused the power to change.Adjusting the power to the maxiumum before transmitting is essential,so adjust the optical fiber four times and use the status of optical fiber of the highest power for subsequent experiments.The architecture of free space are in an air medium under normal atmospheric temperatures and fog. Signal is transmitted after adding a polarizer, and the polarizer angle is adjusted for each 30°. Signal is decoded after signal through free space. In the study, environment testing is simulated by fog, and adds a polarizer to adjust polarization. The results measured at different polarization state of the signal changes in the transmission process.

並列關鍵字

OCDMA ； FBG ； Enviroment testing

參考文獻

[9]吳岳勳，2011, “運用光纖環與光纖光柵於同時測量溫度與位移”，國立虎尾科技大學光電與材料科技研究所論文。

[2] E. Ciaramella, Y. Arimoto, G. Contestabile, M. Presi, A. D’ Errico, V.Guarino, and M. Matsumoto, “1.28-Tb/s (32 x 40 Gb/s) Free-Space Optical WDM Transmission System,” IEEE Photonics Technology Letters, pp. 1121-1123, August, 2009.

[4] Y. Arimoto, “Multi-gigabit free-space optical communication system with bidirectional beacon tracking,” IEE Journal Transmit Fundamentals Mater, pp. 385–390, January, 2007.

[5] K. O. Hill, Y. Fujii, D. C. Johnson, and B. S. Kawasaki, “Photosensitivity in optical fiber waveguides: Application to reflection filter fabrication,” Appl. Phys. Lett., pp. 647– 649, August, 1978.

[7] K.O. Hill, B. Malo, F. Bilodeau, D.C. Johnson, and J. Albert, “Bragg gratings fabricated in

國際替代計量

無線光分碼多工系統於不同偏振光之環境測試

未授權

主題瀏覽