Two Months Field Transmission Test of 2.5-Gb/s Y-00 Cipher in 160-km (40 km × 4 spans) Installed Optical Fiber Cable for Secure Optical Fiber Communications

Field transmission test of 2.5-Gb/s Y-00 cipher in 160-km (40 km 4 spans) is demonstrated in the installed optical fiber, TAMA net #1, for secure optical fiber communications. A long term investigation of an intensity modulated Y-00 transmitter and receiver with signal intensity levels of 4096 is conducted and the bit error rate of < 10-9 for two months is successfully achieved.