1310/1550nm Wavelength Division Multiplexer can make the optical signal of 1310/1550nm transferring in optical fiber coupling in the couple section. It can multiplexe two optical signals of 1310nm and 1550nm wavelength to transfer in a optical fiber(multiplexing), and it can divide from the two optical signals transferr-ing in optical fiber (division). It is the basic unit to build variety high performance Wavelength Division Multiplexer. NDT's Wavelength Division Multiplexer has excellent features of application. Features: 1.Low insertion loss 2.High wavelength isolation 3.Low polarization dependenence 4.Excellent directivity 5.Environmentally stable 6. Return Loss(dB):≥55 7.Directivity(dB):≥60 8.Operating Temperature(℃)-20～+70 9.Storage Temperature(℃)-40～+85 10.Fiber lead length: 1M Applications: 1.Optical fiber communications 2.Optical fibe r access networks 3.Optical fiber CATV 4.Optical fiber instrumentations 5.Optical fiber sensors