SPECTRALLY SELECTIVE SAGNAC-INTERFEROMETE R

We describe theoretically the modified Sagnac interferometer, which ha s spectrally selective output characteristic. Such a spectrally select ivity interferometer may operate as a wavelength division multiplexer (WDM). A polarization-independent Sagnac loop based WDM with bandwidth of 0.5 nm have been demonstrated experimentally. Spectral characteris tic changes with temperature are analyzed. Temperature-induced wavelen gth shift of 1nm/K have been measured.