Fiberized Silicon: A New Platform for Nonlinear Photonics Devices

Lead Research Organisation: University of Southampton
Department Name: Optoelectronics Research Ctr (closed)

Abstract

The age of optical communications has been enabled by two key materials and technological breakthroughs: low loss silica optical fibre waveguides and silicon based electronics. In order to integrate these two technologies, one of which is fibre based and the other planar chip based, the devices have to be interfaced via complex intermediate optics. Clearly the ability to combine the flexible light guiding capabilities of glass fibres with the rich optoelectronic functionality of silicon in an integrated fibre geometry is an exciting prospect. For example, we could then consider building lasers, modulators, switches, detectors and even electronic circuits all inside a compact fibre geometry. This proposal describes research that will follow the development of silicon impregnated optical fibres from the design and characterization stage, to the demonstration of practical all-fibre devices. The fabrication of these hybrid structures will utilize the unique framework of microstructured optical fibres, which contain microscale air holes that run down their length, as 3D templates into which the semiconductor material will be deposited. The proposed structures will form the basis of a number of devices including in-fibre semiconductor lasers, high speed all-optical modulators, broadband sources that extend into the mid-infrared and tuneable photonic band gap fibres (PGBFs). Fiberized silicon devices offer significant advantages such as low cost, versatility, robust waveguide geometries, compactness and highly extended electromagnetic interaction lengths. Importantly, the potential applications of this work extend far beyond the optical telecommunications field to include a wide range of disciplines such as medicine, spectroscopy and security monitoring, ensuring a high level of both scientific and commercial relevance.

Publications

10 25 50
 
Description This project was focused towards the design and characterization of a new class of silicon impregnated optical fibre with the aim to develop a range of all-fibre optoelectronic devices. A number of silicon fibre designs were realized by utilizing the unique microstructured optical fibre (MOF) framework into which the materials were deposited. These MOFs, which contain precisely positioned microscale air holes that run down their length, act as exceptional 3D templates as they are robust, flexible, and can be fabricated in a wide array of patterns to access different waveguiding properties. The silicon MOFs that were produced through this work were the first demonstrations of their kind and allowed for the control of the number of waveguided optical modes and their propagation properties. In addition to these novel fibre designs, much of the efforts of this research programme were directed towards characterizing the linear and nonlinear optical properties of the different silicon materials (crystalline and amorphous). To this end, a hydrogenated amorphous material (a-Si:H) was found to have the most promise for nonlinear applications owing to its low optical losses and high nonlinear coefficient, and was used in the first characterization of nonlinear transmission in the semiconductor core fibres. These a-Si:H core fibres were subsequently demonstrated for signal processing functions such as ultrafast all-optical modulation and switching at telecommunications wavelengths, and they have also shown great promise for longer wavelength applications around 2 microns, of interest for broadband and free space communications. Further investigations were also conducted on the first tapered silicon optical fibres, novel microcylindrical silicon resonators, as well as fibres with different core materials such as germanium, which has a higher nonlinearity than silicon, and zinc selenide, a good material for laser applications. These studies covered a broad wavelength range from the visible to the mid-infrared (500 nanometres-10 microns), so that the potential applications of this work extend far beyond optical telecommunications and into areas such as medicine, spectroscopy, security monitoring and even visual display units.
Exploitation Route These findings could be of use within a number of disciplines. For example, the ultrafast processing aspects could be employed within information and data communications whilst the development of sources that extend into the mid-infrared spectral region could be used for sensing and medical applications.
Sectors Digital/Communication/Information Technologies (including Software),Environment,Healthcare

 
Description EPSRC Research Fellowship
Amount £1,150,136 (GBP)
Funding ID EP/P000940/1 
Organisation Engineering and Physical Sciences Research Council (EPSRC) 
Sector Public
Country United Kingdom
Start 02/2017 
End 02/2022
 
Description EPSRC Responsive Mode
Amount £395,208 (GBP)
Funding ID EP/J004863/1 
Organisation Engineering and Physical Sciences Research Council (EPSRC) 
Sector Public
Country United Kingdom
Start 05/2012 
End 10/2015
 
Description NSF Materials World Network: Semiconductor photonic materials inside microstructured optical fibers
Amount £430,000 (GBP)
Funding ID EP/I035307/1 
Organisation Engineering and Physical Sciences Research Council (EPSRC) 
Sector Public
Country United Kingdom
Start 01/2012 
End 06/2015