Enviroment testing of Free space Optical Code Divide Multiplexing Access system with different polarized light

• Main Authors: Sin-Ting Guo, 郭信廷
• Other Authors: 鄭旭志
• Format: Others
• Language: zh-TW
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/2vztc7

碩士 === 國立虎尾科技大學 === 光電工程系光電與材料科技碩士班 === 104 === 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.