Inkjet-Printed MoS₂ D‑Shaped Fiber for Resonance-Enhanced Optical Sensing

In particular, molybdenum disulfide (MoS₂) has emerged as a versatile 2D material platform for many optical and optoelectronic applications due to its high refractive index, large surface-to-volume ratio, and tunable bandgap. In this work, the integration of MoS₂ layers on a side-polished optical fiber with a D-shaped cross-section has been demonstrated using a low-cost and scalable inkjet printing technique.

The MoS₂-integrated optical fibers are shown to offer strong wavelength-dependent light-matter interactions that can be controlled by the thickness of the 2D material, allowing for tuning of their operation across the entire telecom band. Using a printed device with a MoS₂ layer thickness of 30 nm, designed to exhibit a resonance-enhanced transmission dip at wavelengths of ∼1.50 μm, a refractive index sensor has been demonstrated using saline solutions.