Guided waves systems with embedded two-dimensional materials

Two-dimensional (2D) semiconducting materials are attracting lots of attention from the scientific community because of their unique physical properties, strong light-matter interaction per unit thickness, and van der Waals epitaxy. Amongst them, semiconducting transition metal dichalcogenides (TMDs) are emerging as a potential candidate besides graphene because of their direct band gap at monolayer and substantial nonlinear optical responses. However, the total optical response of 2D TMDs is still low due to their sub-nanometer thinness. In this Dissertation, we overcome that obstacle by growing monolayer TMDs on the guiding core of all-silica exposed-core optical fibers (ECFs) to establish a novel photonic platform using chemical vapor deposition in a scalable manner. We can excite excitons from monolayers and collect PL via guided modes. We demonstrated that our hybrid waveguide can detect NH3 in real-time remote gas sensing with a detection level of less than 125 ppm by monitoring the PL spectrum. Our calculation predicts that we can detect the refractive index change of the environment, for example, from air to water and ethanol by monitoring PL intensity via guided mode. In this work, we have demonstrated that by just a few monolayers on the guiding core, we can enhance third-harmonic generation by 70%. For a 3.5-mm-long fiber, we can increase second-harmonic generation (SHG) more than 1100 times with MoS2-coated ECF compared to the bare fiber. The SHG exhibits an enhancement factor up to 15 times in the resonance to A and B excitons of MoS2. Furthermore, our hybrid waveguides show an χ(2) value of 44 pm/V at 1360 nm. We also found a way to boost the light-matter interaction by coating 25 nm of HfO2 film on top of the guiding core. Altogether, this Dissertation created a versatile photonic platform to grow, characterize, and exploit the intriguing properties of 2D TMDs, which pave the way to the heterogeneous integration era of 2D materials on photonic circuit.