Abstract
Hybrid integration is a key technology for augmenting the functionality of integrated photonic circuits.
Conventional hybrid integration approaches, such as wafer bonding and direct growth, offer the path for
monolithic integration, but are often accompanied with significant complications in the integration processes.
Here, we discuss a novel technique termed transfer printing, which uses an elastomeric stamp to
perform flexible pick-and-place assembly of photonic devices on a chip. With this technique, it is possible
to integrate various photonic elements after the completion of the entire fabrication processes of the
base photonic chips, facilitating hybrid integration on matured integrated photonic platforms, such as silicon
photonics. We review the application of transfer printing for assembling various nanophotonic elements
on silicon photonic chips, with a particular focus on the integration of quantum-dot single photon
sources. We also address other nanophotonic devices realized using transfer printing, such as plasmonic
resonators defined on atomically-flat silver surfaces.
