Objective
Development of a novel low-cost fast multi-element liquid crystal wavefront corrector with a modal influence function and purely digital control is proposed. A modal control principle was already successfully used by us for fabricating modal liquid crystal lenses with focal lengths adjustable in the range 0.5m to infinity. As a multi-element modal device, the new corrector will combine the advantages of both modal lenses (tunability) and zonal correctors (fine-scale aberration correction). Although the new corrector is meant primarily for compensation of aberrations due to the atmospheric turbulence, it can further be used in industry and medicine. Its unique feature is a controllable influence function, which greatly facilitates the simultaneous correction of both large-scale and fine-scale aberrations. As a wave front corrector, the principal element of any adaptive optics system, the proposed device is expected to be a highly competitive alternative for both deformable mirrors and zonal LC correctors.
Fabrication and optimisation of an effective multi-element corrector will be undertaken in 3 interrelated stages:
Construction of a full theoretical model. To study:
steady-state control voltage distributions and integral RC-parameters;
phase response produced by the said distributions;
dynamic analysis with special emphasis on dual-frequency control.
Fabrication of the modal multi-element wavefront corrector, including:
fabrication of glass substrate with fused-in conducting wires;
deposition of high-resistance coating and thin-film dielectric mirror;
primary tests via electrical and optical measurements.
Implementation of the novel control concepts.
investigation of dynamics of the produced modulator for prospective dual-frequency control;
development and fabrication of multi-channel digital-only control unit;
application of the proposed modulator for production of given Zernike modes and real-time wave front correction in a servo-loop system.
The proposed project is a multi-component problem, demanding various research and technological skills. Therefore, four teams from three countries offered to join their efforts to carry out the project.
As the result of this investigations, it is expected:
to find the voltage distributions and the RC-parameters of the proposed corrector in the constant LC impedance approximation;
to develop the software for computer simulations of the electro-optic response of the LC layer of the proposed corrector;
to measure frequency dependencies of the dielectric tensor components for the nematic LC to be used in the modal corrector;
to find optimal parameters of the control voltage spectrum to lower the phase response time of the proposed corrector down to 1 ms;
to fabricate digital-only control unit with a minimum of 37 channels;
to produce the first 10 Zernike modes with the proposed corrector;
to attain the real-time adaptive optics correction of aberrations generated by simulated atmospheric turbulence.
Call for proposal
Data not availableFunding Scheme
Data not availableCoordinator
DH1 3LE Durham
United Kingdom