A theoretical study on deep ultraviolet supercontinuum generation in subwavelength optical fiber

Abstract

In order to obtain supercontinuum (SC) spectra in the deep ultraviolet (UV) region, a generation method of UV SC is proposed based on subwavelength fiber (SWF) composed of background material MgF₂. The nonlinear Schrödinger equation is solved by the split-step Fourier method, the optical fiber transmission characteristics are analyzed by the full-vector finite element, and the evolution of the pumping light into SC is numerically simulated in detail. The results of the numerical analysis show that the SC spectra have a spectral width extending from 229.11 nm to 2366.68 nm when 350 fs input pulses of 6 kW peak power, centered about λ₀ = 400 nm, are launched into a 4 cm long MgF₂ SWF. Such a deep UV SC spectrum has many applications, especially in telecommunication and military fields.