Fused silica optical fibers with graded index nanostructured core

Abstract

The ability to shape the index profile of optical fibers holds the key to fully flexible engineering of their optical properties and future applications. We present a new approach for the development of a graded index fused silica fiber based on core nanostructurization. A graded index core is obtained by means of distribution of two types of subwavelength glass rods. The proposed method allows to obtain arbitrary graded distribution not limited to the circular or any other symmetry, such as in the standard graded index fibers. We have developed a proof of concept fiber with parabolic refractive index core and showed a perfect match between its predicted, designed and measured properties. The fiber has a core composed of 2107 rods of 190 nm of diameter made of either pure fused silica or Ge-doped fused silica with 8.5% mol concentration. The proposed method breaks the limits of standard fabrication approaches used in fused silica fiber technology.

Supercontinuum generation in nanostructured core gradient index fibers

“…The nano-structuration of all-solid fiber also provides a clear mechanical advantage compared to 'holey' fibers (PCFs) and in addition to that, it makes fibers less prone to energy-related damages, due to its "volume glass" nature, compared to air-glass lattice PCFs. We recently introduced and validated experimentally the concept of silica-based single-mode nGRIN fiber (Anuszkiewicz et al 2018). Using numerical simulations, we further demonstrated with a theoretical concept for a potential mid-IR gradient index fiber (Siwicki et al 2017).…”

“…c SEM picture of the developed nGRIN fiber with parabolic core. The lighter areas indicate a distribution of the GeO2-doped silica rods, while the darker ones correspond to fused silica glass (Anuszkiewicz et al 2018) in Fig. 1b.…”

“…Recently, we have introduced the concept of all-glass nanostructured core fibers as a robust solution for industrial applications (Anuszkiewicz et al 2018). In this case, arbitrary refractive index distribution in the fiber can be obtained (Michalik et al 2019).…”

Achromatic nanostructured gradient index microlenses

“…The process of the design of a nanostructured optical element begins with the determination of the desired refractive index distribution, which will be the target function for the design of the glass nanostructure distribution. We have already demonstrated the practical use of this method by fabricating parabolic GRIN microlenses [21], elliptical GRIN microlenses [22], axicon GRIN microlenses [23], diffractive optical elements (DOE) [24], birefringent artificial glass materials [25] as well as fibers with nanostructured parabolic refractive index profile cores [26].…”

Generation of Coherent and Spatially Squeezed States of an Electromagnetic Beam in a Planar Inhomogeneous Dielectric Waveguide

“…This behavior, which allows us to reduce the energy dissipation and distortion of the wave packet shape, is similar to the oscillations of a coherent wave packet in a quantum harmonic oscillator. Today, it is possible not only to put into practice any necessary susceptibility profile due to doping of the dielectric, but also to realize its local control (e.g., by applying voltages to selected electrodes) [9].…”