Peter O. Weigel

Lightwave Circuits in Lithium Niobate through Hybrid Waveguides with Silicon Photonics

We demonstrate a photonic waveguide technology based on a two-material core, in which light is controllably and repeatedly transferred back and forth between sub-micron thickness crystalline layers of Si and LN bonded to one another, where the former is patterned and the latter is not. In this way, the foundry-based wafer-scale fabrication technology for silicon photonics can be leveraged to form lithium-niobate based integrated optical devices. Using two different guided modes and an adiabatic mode transition between them, we demonstrate a set of building blocks such as waveguides, bends, and couplers which can be used to route light underneath an unpatterned slab of LN, as well as outside the LN-bonded region, thus enabling complex and compact lightwave circuits in LN alongside Si photonics with fabrication ease and low cost.

Characterization of a silicon-photonic multi-wavelength power monitor

We describe the design and operation of a silicon-photonic device for monitoring power variations of individual channels in a multi-wavelength DWDM network. Amplitude variations of ~20 dB, for channels spaced by 100 GHz, are measured.