  Graphene is promising for nanoscale, efficient, ultra-fast photo- and
opto-electronic devices because of its remarkable electrical and optical
properties, such as fast electron relaxation and heat dissipation. Here, we
realize high-performance graphene integrated photonics platform enabled by
gold-assisted transfer. Thanks to our optimized transfer technique, we
fabricate and demonstrate (1) a microscale thermo-optic modulator with a tuning
efficiency of 0.037 nm/mW and high heating performance of 67.4
K${\mu}m^{3}mW^{-1}$ on a small active area of 7.54 ${\mu}m^{2}$ and (2) a
graphene electro-absorption modulator featuring an high modulation bandwidth up
to 26.8 GHz and a high-speed data rate reaching 48 Gb/s, and (3) a graphene
Mach-Zehnder interferometer modulator with a high normalized modulation
efficiency of 0.027 dBV$^{-1}{\mu}m^{-1}$. Our graphene integrated photonics
platform has far superior performances compared to state of the art in terms of
efficiency, low process complexity, and compact device footage. Thus, our
approach and results provide the background for the realization of
high-performance integrated photonic circuits with CMOS compatibility.
