Composite material hollow core fibers: functionalization with silicon and 2D materials

Abstract

Hollow Core Anti-resonant fibers allow for guidance of mid-infrared light at low attenuation and can be used for a variety of applications, such as high power laser transmission and gas sensing. Recent work has seen the integration of silicon 1 into such fibers with linear losses potentially as low as 0.1dB/m. Due to the change in refractive index difference of silicon via for example the free carrier plasma dispersion effect, the prospect of an all optical modulator using such a fiber has been proposed 1 . Here, further work has been undertaken on the integration of functional materials inside hollow core fibers via the deposition of the TMD semiconductor material MoS2, in its few-layered form. Through the use of a liquid precursor, a high quality MoS2 film can be deposited over 30cm length of fiber, as confirmed via Raman spectroscopy. The transmission spectra of these novel composite material hollow core fibers has also been analysed, showing additional loss of around 5dB/m, despite being only around 2nm in thickness. This implies that the refractive index of the integrated material is potentially able to modify the guidance properties of the fiber sample. We will present a comparison of the composite material hollow core fibers we have fabricated to date and discuss the prospects for using these novel waveguides in the active manipulation of light, including optical switching, sensing and frequency generation.