Optical fiber poling by induction: analysis by 2D numerical modeling

Optical poling by means of electrical corona discharge

Electrical corona discharge is employed in this work to deposit ions on the surface of an optical fiber, creating a strong electric field that is used for poling. Green laser light propagating in the core frees photocarriers that are displaced by the poling field. The technique presented can induce a higher optical nonlinearity than previously obtained in traditional optical poling with internal metal electrodes. To date, a maximum second order nonlinearity 0.13 pm/V has been achieved for a 15 kV corona discharge bias.

Thermal Poling of Optical Fibers: A Numerical History

This review gives a perspective of the thermal poling technique throughout its chronological evolution, starting in the early 1990s when the first observation of the permanent creation of a second order non-linearity inside a bulk piece of glass was reported. We then discuss a number of significant developments in this field, focusing particular attention on working principles, numerical analysis and theoretical advances in thermal poling of optical fibers, and conclude with the most recent studies and publications by the authors. Our latest works show how in principle, optical fibers of any geometry (conventional step-index, solid core microstructured, etc) and of any length can be poled, thus creating an advanced technological platform for the realization of all-fiber quadratic non-linear photonics.

Single is better than double: theoretical and experimental comparison between two thermal poling configurations of optical fibers

Thermal poling, a technique to create permanently effective second-order susceptibility in silica optical fibers, has a suite of applications including frequency conversion and mixing for high harmonic generation and phase sensitive amplification, optical switching and modulation, and polarization-entangled photon pair generation. In this work, we compare both theoretically and experimentally two different electrode configurations for poling optical fibers, namely double-anode and single-anode, for two different geometries of the cladding holes. This analysis reveals that the single-anode configuration is optimal, both for the absolute value of effective χ ⁽²⁾ created in the fiber core, and for the simplification of the fiber fabrication process.

Thermal poling of multi-wire array optical fiber

We demonstrate in this paper thermal poling of multi-wire array fibers, which extends poling of fibers with two anodes to ~50 and ~500 wire array anodes. The second harmonic microscopy observations show that second order nonlinearity (SON) layers are developed surrounding all the rings of wires in the ~50 anode array fiber with poling of 1.8kV, 250°C and 30min duration, and the outer rings of the ~500 anode array fiber at lower poling temperature. Our simulations based on a two-dimensional charge dynamics model confirm this can be explained by the self-adjustment mechanism, and show the SON layers are induced from the outer rings to the inner rings.