Alliance Fiber Optic Products Inc. has introduced a compact coarse WDM module with 20-nm channel spacing. The company says the SpectraMux provides high center-wavelength accuracy and stability, low insertion loss, high directivity and low polarization-dependent loss in a package that is one-quarter the size of conventional CWDM modules. Featuring wide bandpass characteristics, the mux/demux device is suitable for use with nontemperature-controlled lasers. It is available with four or eight channels and includes an expansion port. Custom wavelengths and channel configurations are offered.