Martijn A. van Eijkelenborg

Microstructured polymer optical fibre

The first microstructured polymer optical fibre is described. Both experimental and theoretical evidence is presented to establish that the fibre is effectively single moded at optical wavelengths. Polymer-based microstructured optical fibres offer key advantages over both conventional polymer optical fibres and glass microstructured fibres. The low-cost manufacturability and the chemical flexibility of the polymers provide great potential for applications in data communication networks and for the development of a range of new polymer-based fibre-optic components.

Fabrication and study of microstructured optical fibers with elliptical holes

We report the fabrication of what are believed to be the first microstructured optical fibers with uniformly oriented elliptical holes. A high degree of hole ellipticity is achieved with a simple technique that relies on hole deformation during fiber draw. Both form and stress-optic birefringence are characterized over a broad wavelength range. These measurements are in excellent agreement with numerical modeling and demonstrate a birefringence as high as 1.0 x 10(-4) at a wavelength of 850 nm.

Continuous-wave ultraviolet light induced fiber Bragg gratings in few- and single-mode microstructured polymer optical fibers

We report observations and measurements of the inscription of fiber Bragg gratings (FBGs) in two different types of microstructured polymer optical fiber: few-mode and an endlessly single mode. Contrary to the FBG inscription in silica microstructured fiber, where high-energy laser pulses are a prerequisite, we have successfully used a low-power cw laser source operating at 325 nm to produce 1 cm long gratings with a reflection peak at 1570 nm. Peak reflectivities of more than 10% have been observed.

Ring structures in microstructured polymer optical fibres

Recent developments in polymer microstructured optical fibres allow for the realisation of microstructures in fibres that would be problematic to fabricate using glass-based capillary stacking. We present one class of such structures, where the holes lie on circular rings. A fibre of this type is fabricated and shown to be single moded for relatively long lengths of fibre, whereas shorter lengths are multimoded. An average index model for these fibres is developed. Comparison of its predictions to the calculated properties of the exact structure indicates that the ring structures emulate homogeneous rings of lower refractive index resulting in the ring structured fibres behaving approximately as cylindrically layered fibres.

Hollow-core microstructured polymer optical fiber

We have fabricated microstructured polymer optical fibers that guide light in a hollow core using the photonic bandgap mechanism. The hollow core allows the use of polymer fibers to be extended to wavelength ranges where material absorption typically prohibits their use, with attenuation lower than the material loss observed in the infrared. The fabrication method is similar to other microstructured polymer optical fibers, which has favorable implications for the feasibility of manufacturing such bandgap fibers.

Recent progress in microstructured polymer optical fibre fabrication and characterisation

Recent progress in microstructured polymer optical fibre fabrication and characterisation will be presented. A wide range of different optical functionalities can now be obtained by modifications of the microstructure, as is demonstrated by the fibres presented here. Microstructured fibres that are single-mode, highly birefringent or show twin-core coupling are described, in addition to graded-index microstructured fibres and hollow core fibres, the latter case being where light is guided in an air core. Microstructured polymer optical fibres are an exciting new development, offering opportunities to develop fibres for a wide range of applications in telecommunications and optical sensing.

Quantum dot and silica nanoparticle doped polymer optical fibers.

A novel and highly versatile doping method has been developed to allow active dopants, including materials incompatible with the polymer matrix, to be incorporated into microstructured polymer optical fibers through the use of nanoparticles. The incorporation of quantum dots and silica nanoparticles containing Rhodamine isothiocyanate is demonstrated.

Imaging with microstructured polymer fibre.

The imaging capabilities of a multicore microstructured polymer optical fibre with a square array of 112 air holes are demonstrated. Coherent imaging is achieved either by guiding light in polymer cores between air holes, or by guiding light in the air channels themselves. This potentially provides a miniaturised endoscope for medical applications, or a two-dimensional parallel optical data link for high-bandwidth interconnects.

Casting preforms for microstructured polymer optical fibre fabrication

A monolithic structured polymer preform was formed by in-situ chemical polymerization of high-purity MMA monomer in a home-made mould. The conditions for fabrication of the preforms were optimized and the preform was drawn to microstructured polymer optical fibre. The optical properties of the resultant elliptical-core fibre were measured. This technique provides advantages over alternative preform fabrication methods such as drilling and capillary stacking, which are less suitable for mass production.

Microstructured polymer fiber laser

A microstructured polymer optical fiber doped with Rhodamine 6G dye was fabricated and demonstrated as an optical amplifier and a fiber laser. As an amplifier, the fiber achieved a gain in excess of 30 dB. As a pulsed fiber laser, the fiber exhibited a threshold of 20 microJ, a slope efficiency of 18%, and a lifetime as high as 130,000 shots at 10 Hz. The maximum output energy was 16 microJ. The advantages that such fibers offer lie in the simplicity and flexibility of their fabrication and in their potential for use as compact, tunable solid-state sources.