Facilities

Fully integrated photonic microwave/millimeterwave (MMW) tracking generators, which include wavelengthtunable lasers, distributed feedback lasers, phase modulators, and high-speed photodiodes (PDs), are demonstrated on the heterogeneous integrated III–V-on-Si photonic platform. Two on-chip lasers are locked by an external optical phase-locked loop (OPLL), and the two-tone radio-frequency (RF) signals from the on-chip fast PDs can be photonically generated through the heterodyne-beating process between the wavelengthtunable laser and the OPLL output.

Optical isolators and circulators are important elements in many photonic systems. These nonreciprocal devices are typically made of bulk optical components and are difficult to integrate with other elements of photonic integrated circuits. This article discusses the best performance for waveguide isolators and circulators achieved with heterogeneous bonding. By virtue of the bonding technology, the devices can make use of a large magneto-optical effect provided by a high-quality single-crystalline garnet grown in a separate process on a lattice-matched substrate.