Application of Polarized Light in Secret Communication
HU Qing 1, WANG Min qi 1, YUAN Sui hua 2 (1. Dept.of Telecom.,Chongqing University of Posts and Telecommunications,Chongqing 400065,China; 2. Dept.of Physics,Southwest China Normal University,Chongqing 400715,China)
The polarity of light transmitting in polarization maintaining fibers in a secret communication system is dependent on artificial and environmental interference in the fiber.The polarity may be taken as sensing parameter to detect in real time the wiretapping.This gives an extra security in addition to the ordinary secret coding.The data of background noise has been set up for the system without wiretapping at temperature in the range of -35～55 ℃.The threshold of wiretapping detecting is defined by the bend radius of the fiber.