  Atomically thin 2D materials provide a wide range of basic building blocks
with unique properties, making them ideal for heterogeneous integration with a
mature chip platform. An understanding the role of excitons in transition metal
dichalcogenides in Silicon photonic platform is a prerequisite for advances in
optical communication technology, signal processing, and possibly computing.
Here we demonstrate passive tunable coupling by integrating few layers of MoTe2
on a micro-ring resonator. We find a TMD-to-rings circumference coverage length
ratio to place the ring into critical coupling to be about 10% as determined
from the variation of spectral resonance visibility and loss as a function of
TMD coverage. Using this TMD ring heterostructure, we further demonstrate a
semi-empirical method to determine the index of an unknown TMD material (nMoTe2
of 4.36+.011i) near for telecommunication-relevant wavelength.
