Comparison of novel liquid electrodes for silica optical fiber thermal poling

We report experimental analysis of optical fibers thermally poled over long lengths using novel types of internal liquid electrodes to generate effective second-order nonlinearities. Our analysis includes transmission losses, depletion region formation, SHG at telecom pump wavelengths

All-fiber fourth and fifth harmonic generation from a single source

All-fiber fourth and fifth harmonic generation from a single source is demonstrated experimentally and analyzed theoretically. Light from a fully fiberized high power master oscillator power amplifier is launched into a periodically poled silica fiber generating the second harmonic. The output is then sent through two optical microfibers that generate the third and fourth harmonic, respectively, via four wave mixing (FWM). For a large range of pump wavelengths in the silica optical transmission window, phase matched FWM can be achieved in the microfibers at two different diameters with relatively wide fabrication tolerances of up to ±5 nm. Our simulations indicate that by optimizing the second harmonic generation efficiency and the diameters and lengths of the two microfibers, conversion efficiencies to the fourth harmonic in excess of 25% are theoretically achievable

Four-wave mixing UV generation in optical microfibers

UV generation via four-wave-mixing (FWM) in optical microfibres (OMFs) was demonstrated. This was achieved by exploiting the tailorable dispersion of the OMF in order to phase match the propagation constant of the four frequencies involved in the FWM process. In order to satisfy the frequency requirement for FWM, a Master Oscillator Power Amplifier (MOPA) working at the telecom C-band was connected to a periodically poled silica fibre (PPSF), producing a fundamental frequency (FF) at 1550.3nm and a second harmonic (SH) frequency at 775.2nm. A by-product of this second harmonic generation is the generation of a signal at the third harmonic (TH) frequency of 516.7nm via degenerate FWM. This then allows the generation of the fourth harmonic (FH) at 387.6nm and the fifth harmonic (5H) at 310nm via degenerate and nondegenerate FWM in the OMF.The output of the PPSF was connected to a pure silica core fibre which was being tapered using the modified flame brushing technique from an initial diameter of 125µm to 0.5µm. While no signal at any UV wavelength was initially observed, as the OMF diameter reached the correct phase matching diameters, signals at 387.6nm appeared. Signals at 310nm also appeared although it is not phase matched, as the small difference in the propagation constant is bridged by other nonlinear processes such as self-phase and cross phase modulation

UV light generation in optical fibres

UV light has been generated in optical fibers using nonlinear optics (harmonic generation) and rare earth doping with Gd3+

UV generation in silica fibres

The generation of UV light in solid core silica fibres has been achieved using four wave mixing in optical fibre tapers or rare earth doping with Gd3+

High pressure CVD inside microstructured optical fibres

We report the fabrication of semiconductor structures within holey fibres via a pressure driven microfluidic chemical vapour deposition process, demonstrating templated growth of crystalline Group IV semiconductor structures and devices in extreme aspect ratio geometries

Semiconductor optical fibre devices

Semiconductor waveguide fabrication for photonics is usually performed in a planar geometry. However, over the past decade a new field of semiconductor-based optical fibre devices has emerged. Using high pressure chemical deposition technology jointly developed by our groups at Penn State and ORC Southampton, crystalline elemental semiconductors such as Si, Ge and even compound II-VI materials such as ZnSe have been chemically deposited at high pressure inside silica capillaries and microstructured optical fibres, allowing the optical and electronic properties of these materials to be exploited for applications such as all-fibre optoelectronics. The high-pressure chemical vapour deposition (HPCVD) technique is simple, low cost, and flexible so that it can be modified to fill a range of complex geometries, thus providing additional design flexibility to enhance the potential application base of the electronic/photonic devices

Borosilicate based hollow-core optical fibers

We discuss the fabrication of hollow-core optical fibers made of borosilicate glass. We show that, despite the high attenuation of the glass relative to silica, the fiber optical losses can be of the same order of magnitude of those obtained by using ultrapure silica glass. Short lengths of the fabricated fibers, used in combination with incoherent optical sources, provide single-mode optical guidance in both near and mid-infrared spectral ranges without any additional optical components.</p

Dataset for proceeding paper: Single is better than double. Analysis of thermal poling configurations using 2D numerical modeling

Dataset supports: De Lucia, F., &amp; Sazio, P-J. (2018). Single is better than double: analysis of thermal poling configurations using 2D numerical modeling. In Proceedings of SPIE Photonics West 2018 SPIE. </span