title: Athermal and flat-topped silicon Mach-Zehnder filters.
abstract: Athermal and flat-topped transmissions are the two main requirements for a silicon WDM filter. A Mach-Zehnder (MZ) filter which simultaneously satisfies these two requirements has been experimentally demonstrated in this paper. A combination of strip waveguide and hybrid strip-slot waveguide is introduced for athermalization, and two-stage interference is utilized for flat-topped transmission. The temperature dependent wavelength shift is measured to be ~-5 pm/K while the best 1 dB bandwidth is 5.5 nm with 14.7 nm free spectral range (FSR). The measured minimum insertion loss is only 0.4 dB with a device dimension of 170 μm × 580 μm. Moreover, Such a MZ filter is compatible with the state-of-art CMOS-fabrication process and its minimum feature size is as large as 200 nm.
authors.forename: Qingzhong
authors.initials: Q
authors.lastname: Deng
authors.forename: Lu
authors.initials: L
authors.lastname: Liu
authors.forename: Rui
authors.initials: R
authors.lastname: Zhang
authors.forename: Xinbai
authors.initials: X
authors.lastname: Li
authors.forename: Jurgen
authors.initials: J
authors.lastname: Michel
authors.forename: Zhiping
authors.initials: Z
authors.lastname: Zhou