Passband flattening and rejection band broadening of a periodic Mach-Zehnder wavelength filter by adding a tuned ring resonator

A thermo-optically tuneable periodic wavelength filter having a rectangular wavelength response with a 50 GHz free spectral range, based on a Mach-Zehnder interferometer with ring resonator has been fabricated in SiON waveguide technology

Passband flattened interleaver using a Mach- Zehnder interferometer with ring resonator fabricated in SiON waveguide technology.

A wavelength interleaver having almost rectangular wavelength response, with 50 GHz free spectral range has been demonstrated using SiON waveguide technology. The device consists of an asymmetric Mach-Zehnder Interferometer (MZI), with a ring resonator coupled to one of its branches. A passband flattened and stopband broadened transfer function with 15 dB isolation for TM polarized light (12 dB for TE) has been measured. The isolation was less than the designed 30 dB due to fabrication errors causing a deviation in coupling coefficient between MZI-branch and ring. The chromatic dispersion was measured to be zero in the center and 1660 ps/nm at the edge of the passband