Dispersion properties of a single-mode windmill single crystal Sapphire optical fiber and its broadband infrared supercontinuum generation

Abstract

The effective refractive indices of each mode of a windmill single crystal sapphire fiber as function of wavelength can be obtained by finite element method. Recently, it is shown that this fiber operates in single-mode condition for a wide wavelength range. The dispersion and the slope of dispersion for the fundamental mode of a windmill single crystal sapphire fiber are properly obtained making use of the measured values of the refractive index as a function of the wavelength. Subsequently, the pulse evolution along this windmill fiber is investigated for low peak power pulses. Due to high applicability of broadband light sources, here, supercontinuum generation process is also studied when high peak power pulses are launched into the single-mode windmill single crystal sapphire fiber. Due to its unique optical properties, the single-mode windmill single crystal sapphire fiber can be used to generate broadband IR supercontinuum light compared with the conventional single crystal sapphire fiber. Our simulation results indicate that generated output spectrum contains dense frequency combs in a wide range. This broadband IR light source facilitates IR spectroscopy while its frequency combs are important in the development and improvement of the optical metrology.