Effect of core size on nonlinear transmission in silicon optical fibers

The nonlinear transmission properties of two hydrogenated amorphous silicon fibers with core diameters of 5.7µm and 1.7µm are characterized. The measured Kerr nonlinearity, two-photon absorption and free-carrier parameters will be discussed in relation to device performance

Mid-infrared transmission properties of step index and large mode area ZnSe microstructured optical fibers

ZnSe microstructured fibers have been designed and fabricated using silica capillaries and an air-silica photonic band-gap optical fiber as high-pressure microfluidic templates for semiconductor growth via chemical fluid deposition. We examine their transmission properties over a wide spectral range

Towards in-fiber silicon photonics

The state of the art of silicon optical fibers fabricated via the high pressure chemical deposition technique will be reviewed. The optical transmission properties of step index silicon optical fibers will be presented, including investigations of the nonlinearities that can be used for all-optical signal processing. In addition, alternative complex fiber geometries that permit sophisticated control of the propagating light will be introduced

Optical characterisation of germanium optical fibres

Semiconductor core optical fibres are currently generating great interest as they promise to be a platform for the seamless incorporation of optoelectronic functionality into a new generation of all-fibre networks [1,2]. Although recent attentions have primarily focused on silicon as the material of choice for semiconductor photonics applications, germanium has some advantages over its counterpart. For example, it has higher nonlinearity, extended infrared transparency and has recently been demonstrated as a direct band gap laser medium [3]. Here we present the first optical characterisation of a germanium core optical fibre. The fibre was fabricated using a chemical micro fluidic deposition process [1] that uses GeH4 (germane) as a precursor to deposit amorphous germanium into the hole of a silica capillary. Figure 1 (a) shows an optical microscope image of the polished end face of a germanium fibre, with a 5.6 µm core diameter, which has been completely filled with the semiconductor material. Optical transmission measurements have been conducted over the wavelength range 2 µm to 11 µm, to confirm the broad mid-infrared operational window, and the guided output at 2.4 µm, imaged using a Spiricon Pyrocam III pyroelectric array camera, is shown in Figure 1 (b). At this wavelength the optical loss has been measured to be 20 dB/cm, which is comparable to losses measured for amorphous silicon fibres in the infrared. The potential for these germanium optical fibres to be used as optical modulators and infrared detectors will be discussed

Surface enhanced Raman scattering using metal modified microstructured optical fibre substrates

We report the fabrication of metallic metamaterials using microstructured optical fibres as templates. The resulting fibres serve as excellent substrates for surface enhanced Raman spectroscopy and represent an exciting platform for in-fibre plasmonic devices

Low power resettable optical fuse based on the amorphous silicon ARROW fiber

We present a silicon antiresonance reflecting optical (ARROW) fiber that has power dependent transmission properties. When the throughput power exceeds a nominal value the transmission band structure closes and the fiber can no longer transmit light

Who needs contacts? Optical fiber poling by induction

Conventional thermal poling methods require direct physical contact to internal fibers electrodes. Here, we report a novel indirect method in which external fields are used to charge floating internal electrodes to generate depletion regions for SHG

Ultrafast all-optical modulation in silicon optical fibers

Degenerate and non-degenerate two-photon absorption based modulation is demonstrated in a hydrogenated amorphous silicon core optical fiber. We show modulation using femtosecond pulses and compare this with theory

Cross-phase modulation in a hydrogenated amorphous silicon optical fiber

We experimentally demonstrate cross-phase modulation (XPM) in a hydrogenated amorphous silicon-silica optical fiber. Additional numerical analysis shows that shifts in the probe wavelength are induced by the pump indicating potential for Kerr based switching applications

Semiconductor fibre devices for nonlinear photonics

A number of technologies are starting to emerge which bring new functionality to optical fibres. In particular, fibres that offer improved nonlinear performance are currently receiving much attention for use in all-optical signal processing. The underlying principles of this field allow for the manipulation of signals carried by light at speeds and capacities far beyond the abilities of electronic systems. Although conventional silica optical fibres have already been demonstrated for applications such as regeneration, switching, and encoding/decoding of information carried in light form, long fibre lengths and high power levels are typically required. New fibre materials that exhibit enhanced nonlinear properties would not only allow for reduced device lengths and lower energy consumption, but they could also be chosen to extend the transmission window beyond that of silica for a wider range of applications. To this end, a new class of fibre that incorporates semiconductor materials into the core was proposed and demonstrated in 2006. Importantly, the ability to intricately control both the optical and electronic properties of semiconductor materials has led to semiconductor photonics becoming one of the largest growing areas of research in recent years. In this poster I will describe my research on the characterization of these semiconductor core fibres with the aim to developing all-optical nonlinear photonic devices