High speed spatial light modulators with analogue phase control for next generation imaging, photonics, and laser manufacturing
Lead Research Organisation:
University of Oxford
Department Name: Engineering Science
Abstract
Abstracts are not currently available in GtR for all funded research. This is normally because the abstract was not required at the time of proposal submission, but may be because it included sensitive information such as personal details.
Publications
Bolis S
(2018)
Solvent-induced self-assembly of uniform lying helix alignment of the cholesteric liquid crystal phase for the flexoelectro-optic effect
in Liquid Crystals
Fells JAJ
(2022)
Dynamic phase measurement of fast liquid crystal phase modulators.
in Optics express
Fells JAJ
(2019)
Dynamic response of large tilt-angle flexoelectro-optic liquid crystal modulators.
in Optics express
Fells JAJ
(2018)
Flexoelectro-optic liquid crystal analog phase-only modulator with a 2p range and 1 kHz switching.
in Optics letters
Hansford D
(2016)
Speckle contrast reduction of laser light using a chiral nematic liquid crystal diffuser
in Applied Physics Letters
Jin Y
(2022)
Backflow-assisted time-resolved phase modulation in nematic liquid crystal Pi-Cells
in Optics & Laser Technology
Jin Y
(2020)
Millisecond Optical Phase Modulation Using Multipass Configurations with Liquid-Crystal Devices
in Physical Review Applied
Salter PS
(2018)
Femtosecond fiber Bragg grating fabrication with adaptive optics aberration compensation.
in Optics letters
Sandford O'Neill J
(2019)
Robust measurement of flexoelectro-optic switching with different surface alignments
in Journal of Applied Physics
| Description | I) Developed a new technique for characterising liquid crystal materials that allows multiple properties to be measured simultaneously and time-resolved. This technique could also be applied to other electro-optic effects in a range of materials and devices. ii) Characterised a number of new liquid crystalline materials which has increased our understanding of the underlying physical properties and provides input optimisation to our collaborators. iii) Devised and simulated a new device architecture which permits full analogue phase modulation at fast switching speeds; iv) Developed a new time-resolved measurement technique for characterising electro-optic phase modulators; v) Demonstrated experimentally a device with full analogue phase modulation at 1 kHz frame rate. |
| Exploitation Route | Implementation of new spatial light modulator in applications involving microscopy, communications, micromachining, beam-steering, and laser range finding. These will find applications in healthcare, aerospace and space engineering, and manufacturing. The phase modulator that was conceived in this research project is now being developed for the Space Sector in partnership with MDA and the European Space Agency. |
| Sectors | Aerospace, Defence and Marine,Chemicals,Digital/Communication/Information Technologies (including Software),Electronics,Healthcare,Manufacturing, including Industrial Biotechology,Transport |
| URL | https://onlinelibrary.wiley.com/doi/full/10.1002/admt.202000589 |
| Description | The research carried out in this project has led to the invention and development of new liquid crystal optical phase modulators. One form of the modulators is currently being developed for use as a non-mechanical beam-steering element for deployment in Space systems for the purposes of optical communication, navigation and docking, and tracking. 'The impact of this work is also recorded against grant ref EP/M016218/1. |
| First Year Of Impact | 2017 |
| Sector | Aerospace, Defence and Marine,Electronics |
| Impact Types | Economic |
| Description | ESA |
| Amount | € 200,000 (EUR) |
| Organisation | European Space Agency |
| Sector | Public |
| Country | France |
| Start | 11/2018 |
| End | 07/2019 |
| Description | Jesus College Major Research Grant |
| Amount | £5,500 (GBP) |
| Organisation | University of Oxford |
| Sector | Academic/University |
| Country | United Kingdom |
| Start | 04/2017 |
| Description | Multipoint Sensors for Extreme Environments |
| Amount | £1,226,073 (GBP) |
| Funding ID | EP/T00326X/1 |
| Organisation | Engineering and Physical Sciences Research Council (EPSRC) |
| Sector | Public |
| Country | United Kingdom |
| Start | 06/2020 |
| End | 05/2025 |
| Description | Visiting Studentship on Flexoelectro-optic Liquid Crystal Devices |
| Amount | £10,000 (GBP) |
| Organisation | Wiener-Anspach Foundation |
| Sector | Charity/Non Profit |
| Country | Belgium |
| Start | 10/2016 |
| End | 08/2017 |
| Title | Time-resolved measurement of birefringence and tilt angle of switched electro-optic devices |
| Description | Certain liquid crystalline materials undergo a change in their retardance and/or angle of optic axis when subjected to an electric field. In order to properly observe these effects it is necessary to use an alternating electric field such as a square-wave with a frequency in the range of 100Hz-1kHz. This presents a challenge as existing high resolution techniques require mechanical continuously rotating elements and it has previously is not been possible to observe changes on these timescales. A brand new measurement concept has been devised and experimentally demonstrated. This allows i) retardance, tilt angle and loss to be measured dynamically against time; ii) retardance and tilt angle to be deconvolved from one another in materials in which both properties change simultaneously; iii) the measurement to be completely automated such that a large parameter space of conditions (e.g. temperature, field strength, frequency) to be explored without human intervention. The measurement system uses only a few standard optical components (e.g. laser, polarisers, waveplate) and several high precision motorised rotation mounts. It has been fully calibrated and found to have an absolute angle accuracy of <0.3 degrees and a retardance error of <0.44 degrees. The relative accuracy is however considerably better than this. The system employs a novel scheme to cancel systematic measurement error by swapping between left-hand and right-hand circularly polarised light. |
| Type Of Material | Improvements to research infrastructure |
| Year Produced | 2017 |
| Provided To Others? | Yes |
| Impact | The measurement allowed us to measure time-resolved tilt-angle and birefringence of flexoelectro-optic devices for the first time. It has allowed us to observe the dynamics of these devices, including the interaction between the rise time and decay due to ionic screening. It has also brought to light a new phenomena, not previously observed, whereby the switching angle is asymmetric with applied electric field under certain conditions. The method therefore allows us to mitigate these effects. We tested a material with high flexoelectro-optic switching, allowing us to observe the angle switching between -45 degrees and +45 degrees against time. It has also allowed us to observe extremely small changes in birefringence, which has not been possible previously, potentially opening up new areas of research in understanding these effects. It is important to note that this Research Tool is completely general and not restricted to the study of liquid crystal materials. We anticipate that this will become the de-facto measurement technique of choice for a wide range of electro-optic materials and underpin research across many application areas. |
| URL | https://www.osapublishing.org/oe/abstract.cfm?uri=oe-26-5-6126 |
| Title | Time-resolved phase modulation capability |
| Description | A new technique for characterising the time-resolved phase modulation of liquid crystal devices and related technologies has been developed. |
| Type Of Material | Improvements to research infrastructure |
| Year Produced | 2019 |
| Provided To Others? | No |
| Impact | The technique allows for the phase modulation to be determined in real time, which is particularly important for the characterisation of liquid crystal and other electro-optic phase modulators. |
| Description | Compact Scanning LIDAR |
| Organisation | NEPTEC UK Limited |
| Country | United Kingdom |
| Sector | Private |
| PI Contribution | We identified that the Spatial Light Modulator being developed in this EPSRC-funded project could enable new classes of compact scanning LIDAR with applications in Space Engineering and elsewhere. As a result, we submitted a proposal with Neptec to the UK Space Agency (National Space Technology Programme, NSTP3-ST, Round 1). We are planning the submission of further proposals to develop the SLM technology for the UK Space Industry. |
| Collaborator Contribution | Neptec submitted proposal as lead contractor. They will be providing contribution in kind in terms of manpower to evaluate the technology. |
| Impact | Submission of proposal to NSTP3-ST Round 1. |
| Start Year | 2016 |
| Title | LIQUID CRYSTAL MODULATOR |
| Description | A device for modulation of light (16) having a wavelength, comprising: a first substrate (10) with a first face (81) and a second opposite face (82), and comprising a first electrode (11); a second substrate (20) adjacent to the second face (82) and defining a gap between the first and second substrate (10, 20), the second substrate (20) comprising a second electrode (21); a responsive liquid crystal layer (15) disposed in the gap, wherein the responsive liquid crystal layer (15) has a flexoelectro-optic chiral nematic phase, and is birefringent with an optic axis that tilts in response to an applied electric field between the first and second electrode (11, 21); and a mirror adjacent to the second substrate (20), the mirror configured to reflect incident circular polarised light while preserving its handedness. |
| IP Reference | WO2020002881 |
| Protection | Patent application published |
| Year Protection Granted | 2020 |
| Licensed | No |
| Impact | This patent forms the basis of the core technology underpinning the development of a new phase modulator that is being developed for LiDAR applications in Space Navigation and Communication systems. |
| Title | Driver for Thorlabs motorized stages |
| Description | During the course of the research it was necessary to control Thorlabs motorised rotation stages from within Matlab, but no Matlab drivers existed. A driver was therefore written to interface Matlab to the Dynamic Link Libraries (DLLs) provided by Thorlabs. The code is written as a self-contained Matlab class definition. Although it is a by-product of this project, it will benefit the wider scientific community as it is a general tool that could be used in many fields of research. The code has been made publically accessible with a BSD license on the Matlab Central File Exchange. |
| Type Of Technology | Software |
| Year Produced | 2018 |
| Open Source License? | Yes |
| Impact | This driver was an essential component of the Time-resolved retardance and optic-axis measurement tool described in the Research Tools section. This tool as had a large impact on this research project and is likely to have significant impact in the wider optical device community. |
| URL | https://uk.mathworks.com/matlabcentral/fileexchange/66497-driver-for-thorlabs-motorized-stages |