Composite Microstructured Optical Fiber Research Articles

Defect core tellurite/phosphate composite microstructured optical fiber with four zero dispersion wavelengths

We propose a novel type of microstructured optical fiber with flattened dispersion curve and four zero dispersion wavelengths. This type of fiber is composed of a defected tellurite core and a phosphate cladding with three rings of air holes along the fiber length. Its dispersion is investigated by using the full-vector finite element method. Numerical results show that the proposed fiber has a flattened dispersion with four zero dispersion points at telecommunication wavelengths. The flattened dispersion and the presence of four zero dispersion wavelengths create a rich phase matching topology, enabling enhanced control over the spectral locations of the four wave mixing and efficiency broadband supercontinuum.

Novel tellurite‐phosphate composite microstructured optical fibers for highly nonlinear applications

AbstractWe propose highly nonlinear composite microstructured optical fibers (CMOFs) which consist of the TeO2‐ZnO‐Li2O‐Bi2O3 (TZLB) tellurite glass core surrounded by a ring of 6 air holes. The fibers were fabricated by a conventional casting rod‐in‐tube method. The size of core and air holes could be con‐trolled easily by inflation pressure. The P2O5‐ZnO‐Na2O‐K2O (PZNK) phosphate glass with similar thermal properties of TZLB was used as a cladding material. Since PZNK glass has low refractive index of 1.511 at 1.54 µm, the refractive index difference between the core and cladding is as large as 0.49 which is favorable to tailor the chromatic dispersion of highly nonlinear optical fibers. To realize zero‐flattened chromatic dispersion, the structure parameters such as the tellurite core diameter, the air hole diameter and the distance between the two neighboring air holes were optimized. As it was shown that zero dispersion wavelengths could be shifted freely from the mid‐infrared region to the telecom window by numerical calculation, we confirmed that our tellurite‐phosphate CMOFs are promising candidates as dispersion tailored highly nonlinear fibers for optical signal processing applications (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Interfacial Energy and Materials Selection Criteria in Composite Microstructured Optical Fiber Fabrication

ABSTRACTThe recently expanding field of microstructured optical fibers relies on the controlled fabrication of sub-micron features in a fiber drawn in the viscous fluid state. Microstructured fibers have generated great interest owing to their potential in areas such as photonic bandgap guidance of light in low-index media; high-energy laser transmission; and unique control over waveguide non-linearities, dispersion and modal properties [1–6]. These fibers have been made from a single material with air holes [7, 8] and as multi-material ‘composite’ fibers where air is not a part of the microstructured region [6, 9]. While single-material microstructured fibers generally rely on the established technology base of fused silica, the use of less conventional materials may enable applications not possible using silica [6]. Multi-material fibers may also present certain fabrication advantages due to their incompressible domains and simple cylindrical geometries. However, the use of more than one material raises questions about which types of materials can be combined in the drawing of a microstructured fiber. This problem can be approached by analyzing the relative importance of different materials properties such as viscosity, interfacial energy, and thermal expansion. In this study we focus on the effects of interfacial energy in composite microstructured fibers. We measure the interfacial energies at high temperature of a chalcogenide glass and an organic polymer recently employed in the fabrication of composite photonic bandgap optical fibers. We discuss the effect of interfacial energy during fiber draw, as well as the interplay between surface and viscous forces. Finally, we comment on the implications of this analysis for understanding what classes of materials can be used in composite microstructured fiber fabrication.