Abstract: The invented modulator provides ultra-high linearity (SFDR=147 dB-Hz), high tolerance, low loss, simple architecture, and low cost. It is based on unique combination of phase-modulator (PM) and ring resonator (RR) that are coupled to the arm(s) of standard Mach-Zehnder interferometer (MZI) configuration. It comprises of input port to receive optical signal 1, optical power separating means 2, interferometer arm length paths 3 & 4, bias controller mean 5, PM 6, RR 7 with coupler 17 having coefficient ?, optical power combining means 8, RF power splitting means 9, RF power source 10, and optical output signal 15. Both PM 6 and RR 7 are driven by same RF source 10 whose output power is divided into two parts with a split ratio of F:(1-F). The role of RR 7 is to provide the necessary non-linear phase-correction. It operates under non-resonance condition to avoid bandwidth narrowing. The dual modulation of PM 6 and RR 7 is an important factor in this invention.

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.