title: Athermal and wavelength-trimmable photonic filters based on TiO₂-cladded amorphous-SOI.
abstract: Large-scale integrated silicon photonic circuits suffer from two inevitable issues that boost the overall power consumption. First, fabrication imperfections even on sub-nm scale result in spectral device non-uniformity that require fine-tuning during device operation. Second, the photonic devices need to be actively corrected to compensate thermal drifts. As a result significant amount of power is wasted if no athermal and wavelength-trimmable solutions are utilized. Consequently, in order to minimize the total power requirement of photonic circuits in a passive way, trimming methods are required to correct the device inhomogeneities from manufacturing and athermal solutions are essential to oppose temperature fluctuations of the passive/active components during run-time. We present an approach to fabricate CMOS backend-compatible and athermal passive photonic filters that can be corrected for fabrication inhomogeneities by UV-trimming based on low-loss amorphous-SOI waveguides with TiO2 cladding. The trimming of highly confined 10 μm ring resonators is proven over a free spectral range retaining athermal operation. The athermal functionality of 2nd-order 5 μm add/drop microrings is demonstrated over 40°C covering a broad wavelength interval of 60 nm.
authors.forename: Timo
authors.initials: T
authors.lastname: Lipka
authors.forename: Lennart
authors.initials: L
authors.lastname: Moldenhauer
authors.forename: Jörg
authors.initials: J
authors.lastname: Müller
authors.forename: Hoc Khiem
authors.initials: HK
authors.lastname: Trieu