| abstract |
A general multi-function optical filter for future smart, high density wavelength division multiplexed (WDM) communication and network system applications using a Michelson-GT interferometer (MGTI) is invented. MGTI filter is a typical Michelson interferometer in which one of its reflecting mirrors is replaced by Gires-Toumois resonator (GTR). One unique feature of this device is that it can function as channel passing, channel dropping and wide bandpass filters depending on the interferometer arm length difference. The output of these functions is available in a single port. Other interesting features of this element are (1) that linewidths of both channel dropping and channel passing filters are twice as narrow compared with typical Fabry-Perot filter having similar parameters, (2) that visibility of the output for three functions is always unity regardless of the mirror reflectance value, and (3) that bandpass filter has an excellent, near-perfect, box-like response function. Numerical results showing these characteristics are presented and other applications are discussed. |