Sidewall control of multistate switchable photonic devices
Lead Research Organisation:
University of Strathclyde
Department Name: Mathematics and Statistics
Abstract
The development of multilevel, multistable switchable phase structures is of significant importance for photonic switching since bi/multistability in optical telecommunications switches will enable (i) enhanced network security after a power outage, since the device would continue to operate and be optically transparent, and (ii) redundancy management, where semi permanent re-routing can easily be implemented. In this project, we build on recent work where we have demonstrated the possibility of not only bistability, but multistability, by micro-structuring the sidewall in a planar aligned liquid crystal layer in order to control alignment. Such azimuthal bistability has previously been reported in liquid crystal devices using surface gratings, surface bi-gratings and periodic arrays of posts on one of the confining substrates. However, in the proposed work the use of the sidewall avoids the need for index matching with surface structures and allows for more functionality in the substrate surface, for instance so that it can be used as an active waveguide cladding. The collaboration between an applied mathematician, Dr Mottram (Strathclyde University), and a materials physicist, Dr Brown (Nottingham Trent University), has allowed this new approach to develop from theoretical possibility to a practical demonstration of feasibility. The proposed project seeks funding to create novel structures that possess stable static states, to investigate dynamic switching between the states, and to investigate the optical and diffractive properties of multistable structures.
People |
ORCID iD |
Nigel Mottram (Principal Investigator) |
Publications
C.L. Trabi (Co-Author)
(2008)
Flexoelectric polarisation effects in nematicliquid crystal phase gratings
DAVIDSON A
(2011)
Conformal mapping techniques for the modelling of liquid crystal devices
in European Journal of Applied Mathematics
Davidson AJ
(2010)
Defect trajectories and domain-wall loop dynamics during two-frequency switching in a bistable azimuthal nematic device.
in Physical review. E, Statistical, nonlinear, and soft matter physics
Evans C
(2010)
Static alignment states in a bistable azimuthal nematic device with blazed grating sidewalls
in Journal of Physics D: Applied Physics
Ladak S
(2009)
Sidewall control of static azimuthal bistable nematic alignment states
in Journal of Physics D: Applied Physics
Trabi C
(2008)
Interferometric method for determining the sum of the flexoelectric coefficients (e1+e3) in an ionic nematic material
in Applied Physics Letters
Tsakonas C
(2007)
Multistable alignment states in nematic liquid crystal filled wells
in Applied Physics Letters
Walton J
(2018)
Nematic liquid crystal director structures in rectangular regions.
in Physical review. E
Description | The development of multilevel, multistable switchable phase structures is of significant importance for many photonic devices. In this project, we built on recent work where we have demonstrated the possibility of not only bistability, but multistability, by micro-structuring the sidewall in a planar aligned liquid crystal layer in order to control alignment. Such azimuthal bistability has previously been reported in liquid crystal devices using surface gratings, surface bi-gratings and periodic arrays of posts on one of the confining substrates. However, in this work the use of the sidewall avoids the need for index matching with surface structures and allows for more functionality in the substrate surface, for instance so that it can be used as an active waveguide cladding. The collaboration between applied mathematics and materials physics has allowed this new approach to develop from theoretical possibility to a practical demonstration of feasibility. An addition finding was that a simplified model of the liquid crystal device, using only a director_based approach, was found to match surprisingly well with the more complicated Q_tensor model, even during dynamic switching of the system, and was considerably less intensive in terms of computer resources. |
Description | Joint research with University of Nottingham-Trent |
Organisation | Nottingham Trent University |
Country | United Kingdom |
Sector | Academic/University |
PI Contribution | University of Strathclyde researchers worked on this project with researchers from University of Nottingham-Trent |
Start Year | 2007 |
Description | Joint research with University of Nottingham-Trent |
Organisation | Nottingham Trent University |
Country | United Kingdom |
Sector | Academic/University |
PI Contribution | University of Strathclyde researchers worked on this project with researchers from University of Nottingham-Trent |
Start Year | 2007 |