Bandpass Wavelength-Division Multiplexers use a multilayer interference filter to separate closely spaced wavelengths. The narrow-band filters allow transmission of u¥to four wavelengths in the 1530-1560-nm region. A three-port passband filter version is used for bidirectional transmission of 1533- and 1557-nm wavelengths on a single fiber. A four-port model is used for bidirectional amplification systems. The devices are epoxy-free in the optical path and have wavelength-temperature stability better than 0.02 nm/°C.
E-TEK Dynamics, San Jose, CA